From 9b873693bdcbfe439a4157564ece781f67e58239 Mon Sep 17 00:00:00 2001 From: Travis CI Date: Thu, 9 May 2019 20:35:45 +0000 Subject: Gem 01b1861db023a225d01a4d5a519cf54f09f631f5 linux/amd64 built 'master:01b1861db023a225d01a4d5a519cf54f09f631f5' for linux/amd64 --- Gem/manual/Advanced.html | 54 +- Gem/manual/BasicObj.html | 230 ++++---- Gem/manual/GemFaq.html | 1334 +++++++++++++++++++++---------------------- Gem/manual/GemWPd.html | 280 ++++----- Gem/manual/Gloss.html | 82 +-- Gem/manual/Images.html | 224 ++++---- Gem/manual/Input.html | 38 +- Gem/manual/Intro.html | 124 ++-- Gem/manual/Lighting.html | 214 +++---- Gem/manual/ListObjects.html | 462 +++++++-------- Gem/manual/Particles.html | 38 +- Gem/manual/Pixes.html | 210 +++---- Gem/manual/Texture.html | 252 ++++---- Gem/manual/Utility.html | 298 +++++----- Gem/manual/WriteCode.html | 82 +-- Gem/manual/index.html | 134 ++--- 16 files changed, 2028 insertions(+), 2028 deletions(-) (limited to 'Gem/manual') diff --git a/Gem/manual/Advanced.html b/Gem/manual/Advanced.html index 5c2a5f2..e23b090 100644 --- a/Gem/manual/Advanced.html +++ b/Gem/manual/Advanced.html @@ -1,27 +1,27 @@ - - - - - - - Advanced - - - -
-

-Advanced objects

- -


Todo: -

more than 8 lights -
pix_imageInPlace -
accumrotate -
camera -
polygon and curve -
text3d -
pix_data -
linear_path -
spline_path -

[return] - - + + + + + + + Advanced + + + +

+

+Advanced objects

+ +


Todo: +

more than 8 lights +
pix_imageInPlace +
accumrotate +
camera +
polygon and curve +
text3d +
pix_data +
linear_path +
spline_path +

[return] + + diff --git a/Gem/manual/BasicObj.html b/Gem/manual/BasicObj.html index 80e5d84..b65dc68 100644 --- a/Gem/manual/BasicObj.html +++ b/Gem/manual/BasicObj.html @@ -1,115 +1,115 @@ - - - - - - - Basic Objects - - - -

-

-Basic Objects

- -


There are a number of objects which are the foundation for GEM. -These objects are used in every patch and control the graphics and rendering. -

[gemwin] - The window manager -
[gemhead] - The start of a rendering chain -
manips - Move an object in the window -
geos - Render a shape -

-

-[gemwin]

-The graphics window is created and destroyed with the [gemwin] object. -With the [gemwin] object, you can set the default size of the graphics -window, create and destroy the graphics window, turn on and off rendering, -etc. All basic GEM patches will have the following [gemwin] -object with these messages: -
-

-The create and destroy messages will display and remove the graphics window. -The 1 and 0 messages start and stop rendering. -

-

-[gemhead]

-The [gemhead] object is the start of every rendering chain. -A simple patch, which is located in examples/gem_basic/gem1.redSquare.pd -looks like: -
-

- -

This patch will render a red square. The [gemhead] object -signifies the start of rendering. The [color] object sets the color -for all objects after it in the chain. The [square] object renders -a square into the graphics window based on the current color, texturing, -and transformations. In this case, there is no texturing and no transformation. -

Every rendering chain MUST start with a [gemhead]. If you -do not put a [gemhead] at the beginning of the chain, then nothing -will be rendered for that part of the patch. -

-

-manips

-In the patch 01.basic/02.cube.pd, the [translateXYZ] object is -introduced. -
-

- -

The graphics are transformed and moved by the manipulator objects, -or the manips. GEM has the following manips: -

[color] - set the color with a vector -
[colorRGB] - set the color with 3 discrete values -
[rotate] - rotate with an angle and vector -
[rotateXYZ] - rotate with 3 discrete values -
[scale] - scale with a vector -
[scaleXYZ] - scale with 3 discrete values -
[translate] - translate with a vector -
[translateXYZ] - translate with 3 discrete values -

To understand the difference between the vector and discrete values -version, realize that everything in is defined in 3 dimensions. These -dimensions can be XYZ values, or RGB colors. -

-

- -

The two translate objects above will do exactly the same thing in a -patch, but they provide two different ways to do it. [translate] accepts -a scalar and vector. [translateXYZ] accepts three floats which -specify a point in space. The manips will transform any object which -appears after it in the rendering chain. -

-

-geos

-Up above, we saw the [square] and [cube] objects. The other -primary geos are: -

[square] - render a square -
[circle] - render a circle -
[triangle] - render a triangle -
[cube] - render a cube -
[sphere] - render a sphere -
[cone] - render a cone -

The [square], [circle], [cube], and [triangle] objects -have a right-hand inlet to set the size of the shape. The default -size is 1. -

The [cone] and [sphere] objects are not perfectly smooth. -They are actually composed of a number of polygons. In order to control -the rendering better, the middle inlet is the size of the object, while -the right-hand inlet is the number of slices to define the shape. -Take a look at the patch gem_basic/gem3.sphere.pd to see how the number -of slices can change the look of a sphere. Don't worry about the -[world_light] -object, it is just there to make it easier to see the difference in the -number of slices. Make sure to click the 'lighting 0' message before -closing the patch (if you don't, then other patches will probably be completely -black until you quit and restart pd/GEM). -

Your graphics window should look like this for 5 and 15 slices: -

-

-Obviously, the more slices that you use, the better the sphere looks. -However, each slice adds more polygons, which can slow down your frame -rate. In computer graphics, there is always a trade off between resolution -and speed. -

-

[return] -
- - + + + + + + + Basic Objects + + + +

+

+Basic Objects

+ +


There are a number of objects which are the foundation for GEM. +These objects are used in every patch and control the graphics and rendering. +

[gemwin] - The window manager +
[gemhead] - The start of a rendering chain +
manips - Move an object in the window +
geos - Render a shape +

+

+[gemwin]

+The graphics window is created and destroyed with the [gemwin] object. +With the [gemwin] object, you can set the default size of the graphics +window, create and destroy the graphics window, turn on and off rendering, +etc. All basic GEM patches will have the following [gemwin] +object with these messages: +
+

+The create and destroy messages will display and remove the graphics window. +The 1 and 0 messages start and stop rendering. +

+

+[gemhead]

+The [gemhead] object is the start of every rendering chain. +A simple patch, which is located in examples/gem_basic/gem1.redSquare.pd +looks like: +
+

+ +

This patch will render a red square. The [gemhead] object +signifies the start of rendering. The [color] object sets the color +for all objects after it in the chain. The [square] object renders +a square into the graphics window based on the current color, texturing, +and transformations. In this case, there is no texturing and no transformation. +

Every rendering chain MUST start with a [gemhead]. If you +do not put a [gemhead] at the beginning of the chain, then nothing +will be rendered for that part of the patch. +

+

+manips

+In the patch 01.basic/02.cube.pd, the [translateXYZ] object is +introduced. +
+

+ +

The graphics are transformed and moved by the manipulator objects, +or the manips. GEM has the following manips: +

[color] - set the color with a vector +
[colorRGB] - set the color with 3 discrete values +
[rotate] - rotate with an angle and vector +
[rotateXYZ] - rotate with 3 discrete values +
[scale] - scale with a vector +
[scaleXYZ] - scale with 3 discrete values +
[translate] - translate with a vector +
[translateXYZ] - translate with 3 discrete values +

To understand the difference between the vector and discrete values +version, realize that everything in is defined in 3 dimensions. These +dimensions can be XYZ values, or RGB colors. +

+

+ +

The two translate objects above will do exactly the same thing in a +patch, but they provide two different ways to do it. [translate] accepts +a scalar and vector. [translateXYZ] accepts three floats which +specify a point in space. The manips will transform any object which +appears after it in the rendering chain. +

+

+geos

+Up above, we saw the [square] and [cube] objects. The other +primary geos are: +

[square] - render a square +
[circle] - render a circle +
[triangle] - render a triangle +
[cube] - render a cube +
[sphere] - render a sphere +
[cone] - render a cone +

The [square], [circle], [cube], and [triangle] objects +have a right-hand inlet to set the size of the shape. The default +size is 1. +

The [cone] and [sphere] objects are not perfectly smooth. +They are actually composed of a number of polygons. In order to control +the rendering better, the middle inlet is the size of the object, while +the right-hand inlet is the number of slices to define the shape. +Take a look at the patch gem_basic/gem3.sphere.pd to see how the number +of slices can change the look of a sphere. Don't worry about the +[world_light] +object, it is just there to make it easier to see the difference in the +number of slices. Make sure to click the 'lighting 0' message before +closing the patch (if you don't, then other patches will probably be completely +black until you quit and restart pd/GEM). +

Your graphics window should look like this for 5 and 15 slices: +

+

+Obviously, the more slices that you use, the better the sphere looks. +However, each slice adds more polygons, which can slow down your frame +rate. In computer graphics, there is always a trade off between resolution +and speed. +

+

[return] +
+ + diff --git a/Gem/manual/GemFaq.html b/Gem/manual/GemFaq.html index fe2e175..1fe41cd 100644 --- a/Gem/manual/GemFaq.html +++ b/Gem/manual/GemFaq.html @@ -1,667 +1,667 @@ - - - - - - - Gem FAQ - - - -

-

-GEM FAQ

- -


* : new question -
+ : changed question -

-

-QUESTIONS

-GENERAL -
1.1) What is GEM? -
1.2) What is Pd? -
1.3) What platforms do GEM and Pd run on? -
1.4.0) How do I install GEM and Pd on IRIX? -
1.4.1) How do I install GEM and Pd on linux? -
1.4.2) How do I install GEM and Pd on WinNT? -
1.7) What is a good intro to OpenGL? -
1.8) Are there any web sites for Pd or GEM? -
1.9) What libraries does GEM use? (aka: Who does Mark -want to thank?) -
1.10) Are there any restrictions on GEM? -
1.11) How do I use GEM in a performance? -

USING GEM -
2.1) How do I (???) -
2.2) How do I make GEM run? -
2.3) Why doesn't GEM run? -
2.4) I've got it running. Now what? -
2.5) On IRIX 5.3, why does GEM dump with an rld error? -
2.6) Why can't I compile GEM on IRIX 5.3? -
2.7) Why is GEM slow in general? -
2.8) Why is GEM slow on IRIX? -
2.9) Why is GEM slow on WinNT/Win95? -
2.10) Why is GEM slow on Linux? -
2.11) If I resize the window, everything looks strange. -
2.12) Can GEM run on a 3Dfx Voodoo card? -
2.13) Will GEM support hardware transform and lighting -(T&L) ? -
2.14) I get an error "GEM needs Truecolor visual support". -

VIEWING OBJECTS -
3.1) Why does everything seem dim? -
3.2) Why does everything seem dark? -

TEXTURE MAPPING -
4.1) My image doesn't appear. What is going on? -
4.2) My image looks strange. What is going on? -
4.3) Why does GEM say that it can't handle a gray image? -
4.4) What image formats can GEM handle? -
4.5) What movie formats can GEM handle? -
4.6) Why is pix_draw so slow? -

WORKING WITH PD -
5.1) Why do I get clicks in the audio? -
5.2) How do I get audio data to GEM? -
5.3) Why can't GEM find an image/model file? -
5.4) How can I optimize my patches? -

WRITING NEW GEM OBJECTS -
6.1) How do I write a new GEM object? -
6.2) What are the default OpenGL states? -

OBJECT SPECIFIC -
7.1) Why doesn't <object> exist on <platform>? -
7.2) Why doesn't gemtablet work? -
7.3) I don't want GEM to take over my tablet. -How do I stop it? -
7.4) Why doesn't gemmouse work in IRIX/Linux? -
7.5) Why doesn't gemorb work? -
7.6) What is wrong with pix_video in WinNT? -

-

-ANSWERS

-

GENERAL

-
1.1) What is GEM? -

GEM is the Graphics Environment for Multimedia. -It was originally written by Mark Danks to generate real-time computer -graphics, especially for audio-visual compositions. It originally ran under -FTS/Max (which is why you might see some papers reference it), but all -new development is under Pd. -

You can get GEM at http://gem.iem.at/ -

GEM was sponsored by a grant from Intel (http://www.intel.com) -

GEM was ported to linux by Günter Geiger -

GEM is now maintained by IOhannes m zmölnig. -

the core-development team consists of

-lots of contributions are made by various people (thanks to all of them) -

---- -
1.2) What is Pd? -

Pd is a real-time environment for audio and MIDI. -It was written by Miller Puckette, who created FTS/Max when -he was at IRCAM. Basically, Pd can be seen as the next generation -of real-time visual programming languages. GEM runs inside of the -Pd environment. -

You can get Pd at http://www.crca.ucsd.edu/~msp/software.html -

Pd is sponsored by a grant from Intel (http://www.intel.com) -

---- -
1.3) What platforms do GEM and Pd run on? -

GEM and Pd run on Windows (95, 98, ME, NT 4.0, 2000, XP), linux and macOS-X (>10.2). -SGI-Irix (> 6.2) used to be supported but i don't have any prove that it still works). -Günter Geiger -has done an initial port of GEM and Pd to Linux http://gige.epy.co.at). -

GEM is now maintained by me and -developed by a team of several independent programmers (see section 1.1) -

---- -
1.4) How do I install GEM ? -

---- -
1.4.0) How do I install GEM and Pd on IRIX? -

See the readme for installing Pd. -

GEM should be at -

pd/gem -

If you run GEM.INSTALL.sh, then all of the example files and documention -should be put in the correct locations. -

---- -
1.4.1) How do I install GEM and Pd on linux? -

See the readme for installing Pd. -

GEM should be at -

chdir to <gem>/src/Gnu and build Gem following the instructions in the README.build -(./configure; make) -

If you then make install, then all of the example files and documention -should be put in the correct locations. -

if you are using debian, Gem should be available via apt

-

if you are using an rpm-based distribution, check out the builds at planetCCRMA

-

---- -
1.4.2) How do I install GEM and Pd on WinNT? -

See the readme for installing Pd. -

unzip GEM so that it is at -

pd\gem -

If you run GEM.INSTALL.bat, then all of the example files and documentation -should be put in the correct locations. -

there is also an installer for windows. -

---- -
1.4.3) How do I install GEM and Pd on macOS? -

See the readme for installing Pd. -

there is also an installer for macOS. -

---- -
1.7) What is a good intro to OpenGL? -

The best book is the OpenGL Programming Manual -by Mason and Woo. This is also called the "Red Book". If you search -the web, there are many sites on OpenGL. A good starting point is -http://www.opengl.org. -Also, Mark Kilgard (who used to work for SGI) has a wonderful site with -lots of links (http://reality.sgi.com/mjk) -Also, Normal Lin has written another great book on 3D-graphics under linux -

---- -
1.8) Are there any web sites for Pd or GEM? -

Except for the ones noted above, there is the Japanese -installation page at -
http://www.rinc.or.jp/~kotobuki/gem/index.htm -

There is a Pd mailing list. Subscription info -is on IEM's site http://www.iem.at/mailinglists/pd-list -

One of pd's unofficial home-pages is at http://pd.iem.at hosted by the -Institute of Electronic Music and Acoustics, Graz, Austria -

Also hosted by the iem is the site of the pd-community -http://www.puredata.info -

An interesting place might also be Günter Geiger's size http://gige.epy.co.at/ -

there are lot's of other cool pages (search the net...) -

---- -
1.9) What libraries does GEM use? -(aka: Who does Mark want to thank?) -

All copyrights and license info can be found in -
GEM.LICENSE.TERMS -
Thanks to Sam Leffner for libTiff, the TIFF image -loader. -
-sam@engr.sgi.com -
ftp://ftp.sgi.com/graphics/tiff/ -
Thanks to Masayuki Matsumoto for fstimage for OpenGL, -the SGI -
image loader. -
-matumot@dst.nk-exa.co.jp -
Thanks to the Independent JPEG Group for libjpeg, -the JPEG image loader. -
-jpeg-info@uunet.uu.net -
ftp://ftp.simtel.net/pub/simtelnet/msdos/graphics/ -
Thanks to Mark Kilgard at al. (and SGI) for glut, the openGL Utility Toolkit -
http://www.pobox.com/~ndr -
Thanks to Stephane Rehel for GLTT, the OpenGL TrueType -render. -
-rehel@worldnet.fr -
http://home.worldnet.fr/~rehel/gltt/gltt.html -
Thanks to David Turner, Robert Wilhelm, and Werner -Lemberg for -
Freetype, a TrueType font -rendering engine. -
-turner@enst.fr -
-robert@physiol.med.tu-muenchen.de -
-a7971428@unet.univie.ac.at -
http://www.physiol.med.tu-muenchen.de/~robert/freetype.html -
Thanks to the MPEG Software Simulation Group, for -libmpeg, the -
MPEG-2 Encoder/Decoder -
-mssg@mpeg.org -
http://www.mpeg.org/MSSG/ -
Thanks to Heroine for quicktime4linux -a quickime Decoder -and libmpeg3, another MPEG-2 Encoder/Decoder -
MPEG-2 Encoder/Decoder -
-mssg@mpeg.org -
http://heroinewarrior.com/ -
Thanks to LCS/Telegraphics for Wintab, the Windows -tablet library. -
-wintab@pointing.com -
Thanks to David McAllister for the Particle System -library. -
-davemc@cs.unc.edu -
http://www.cs.unc.edu/~davemc/Particle/ -
Thanks to John Stone for the Space Orb library, -libOrb -
-j.stone@acm.org -
http://www.umr.edu/~johns/projects/liborb/ -

---- -
1.10) Are there any restrictions on GEM? -

GEM is under the Gnu Public License. This basically -means that it will always be free software.Check out http://www.gnu.org -for more information and read the full license in GnuGPL.LICENSE in the GEM release. -

---- -
1.11) How do I use GEM in a performance? -

This is a constant problem, because there is no consistent -way to display video on any platform. Also, you usually do not want -to send the entire screen, but only the GEM window. It is also useful -to be able to edit/control the Pd patch window while the patch is actually -running. -

On SGIs, the best way is to get a video out option. -On the SGI O2, Impact, and Onyx (Mark has used all of these), there is a -simple connector or breakout box to do video. -If you run the video out program, then you will get a rectangle on your screen -which shows what is being sent out the video connector. -Make your GEM window a little larger than 640x480 and center it in the rectangle. -You can now project this with a standard video projector. -

On PCs it is a bit harder. -Several modern video-cards have the possibility to output several screens -(either 2 (or more) VGA-screens or 1 VGA-screen and 1 TV (Composite or S-HVS) -or a combination with DFTs) -If you have a Canopus Voodoo2 card it has a video and s-video output on it. As described -in question 2.12, you can get a Voodoo to work with -GEM. If any one else has a better solution, please let me know. -The nVidia Riva TNTs require that you output the full screen, so this is -not a very good option. You can use a video scan convertor. -Some of them only display a part of the scene, which is exactly what you -want. -

With modern multi-headed cards it is more simple: -Configure your card to display the desktop spread over your multiple screens -(e.g.: from left-to-right). -On windows and macOS you can do this via the display-properties dialog. -On linux you will have to edit your /etc/X11/XF86Config-4 file either by hand or -(if your system supports it) via an appropriate editor (yes, nowadays there are some). -Now create your gem-window on the second screen: -it should have the same dimensions as the 2nd screen (e.g: "[dimen 800 600("). -to place it at the second screen use the offset (e.g: if your primary sreen -(the one you want for patch-editing) has the dimension 1024x768 use "[offset 1024 0(", -which will create the gem-window 1024 pixels right of the upper-left corner -of the total screen (and 0 pixels below it), -which is exactly the upper-left corner of the 2nd screen. -You most probably want to turn off the borders with "[border 0(".
-Note: some grafix-card have openGL-hardware-acceleration only on the 1st screen -(so you should create the gem-window on the 1st screen and move -your patches to the 2nd screen) -

If you are using an XServer for displaying (under linux) you can also use another -computer for rendering. -You can specify the place where the gem-window should be created with something like -"create <render.host>:0.0" - -

If you are doing audio with graphics, the only solution -to prevent clicking (question 5.1) is to run 2 computers -and have them communicate with netsend/netreceive. We are working -on making Pd/GEM multi-processor friendly, so if you have a multi-processor -system, you can run everything on one machine eventually. -

-

USING GEM

-
2.1)How do I (???) -

Many of the general usage questions are probably -answered in the manual or release notes. The pd mailing list is also -a good place to find answers as well. -

2.2) How do I make GEM run? -

GEM is not an executable. It requires Pd to -work and is loaded in at run time. For example, I have an alias on -the SGI which does -

/usr/people/mdanks/pd/bin/pd -lib /usr/people/mdanks/pd/gem/Gem -

and on WinNT -

\pdDir\pd\bin\pd -lib /pdDir/pd/gem/Gem -

on UNIX-systems you will probably want to use a .pdrc file, - where you can put the command-line arguments for pd that you "always" need. -

If you don't see a startup message from GEM, then something went wrong. -

Most people use use the command shell to start Pd. -It is not very difficult to configure Pd to run from double-clicking on the icon. -

---- -
2.3) Why doesn't GEM run? -

Notice that the -lib flag always requires Unix -styles slashes. This is the case even on Windows. -

You may also want to use the -nosound flag. -For instance, my PC has problems using audio (it leaks memory), so I just -turn off the audio part of Pd. However, other people can't get GEM -to work if the -nosound is used (on Win95). You can also try the --dac or -adc flags (for digital-analog-conversion only and analog-digital-conversion -only). -

---- -
2.4) I've got it running. Now what? -

Try out the manual. It will step you through -the basics. -
You will also want to look at the example files. -Assuming that everything is installed correctly, you can get to the examples -by going to the Help menu in Pd and selecting examples. A bunch of -the patches should start with gem<something>. The best one is -gem/01.basic/01.redSquare.pd -It puts a red square up on the screen and allows you to rotate it. gemImage.pd -shows how to load in a TIFF file. gem/03.lighting/04.moveSpheres.pd -moves two spheres around the screen. Try the other ones. -
Most of the GEM objects have test patches which -give some information about the various controls for the object. -

---- -
2.5) On IRIX 5.3, why does GEM dump with an rld error? -

GEM only works under IRIX 6.2+. The rld error -is probably something about not having glBindTextureEXT (or something). -OpenGL 1.0 has some extensions to speed up texture mapping (which are an -integral part of OpenGL 1.1). However, these don't exist on IRIX -5.3. If you recompile GEM (see the next question), things should -work fine. -
I don't have access to an IRIX machine, so don't -expect any builds from me. Upgrading to IRIX 6.2+ is worth it. -

---- -
2.6) Why can't I compile GEM on IRIX 5.3? -

There was probably an error saying that the compiler -couldn't find the file "dmedia/vl_vino.h" in pix_videoSGI.cpp. IRIX -6.2+ adds new functionality to the media libraries which makes life much -easier. You cannot compile pix_video or pix_indycam as is under 5.3. -You can remove them from the Pix/Makefile and from the linker part of the -global Makefile. You will also need to recompile the Td and Tiff -libraries. -

There shouldn't be any problems doing this. I haven't tried any -of this, so if it works for someone, please let me know. -

---- -
2.7) Why is GEM slow in general? -

Examine what you are doing. If you are constantly -changing textures, then this is probably your problem. If you have -models with a million triangles, then this is probably the problem. -Compare what you are doing with realistic specs on your system. Some -systems slow down when they have to draw very large polygons (slow fill -rate). -
You can also turn on profiling to see how long it -takes to render a frame. Send a profile message to the gemwin object. -The number that is printed is the number of milliseconds one frame takes -to render. 50 milliseconds is 20 frames per second. 'profile 2' is -good if you want to see how long the image processing is taking. -
profile 0 - turn off profiling -
profile 1 - turn on profiling -
profile 2 - turn on profiling -and don't cache pixes -

---- -
2.8) Why is GEM slow on IRIX? -

If you are having major slowdowns, then please let -me know. I have gotten very good performance on most machines (Indy, -O2, Impact, Onyx2). -

---- -
2.9) Why is GEM slow on WinNT/Win95? -

You probably don't have hardware acceleration. -You can use software rendering, but it basically useless except for extremely -basic patches. You can get a good graphics accelerator for really -cheap these days. I recommend a card based on nVidia's chipsets, -such as the TNT2 or GeForce, but there are other companies such as 3dfx -and Matrox. Make sure that you are running the latest drivers for -your card. The basic drivers that come with the cards are usually -very bad. -
Also, PCs don't deal with lots of texture maps very -well (they are bus limited, at least until AGP), so if you are trying to -use lots of constantly changing texture maps -(especially with [pix_multiimage], [pix_video] or [pix_film]), that will cause problems. -

---- -
2.10) Why is GEM slow on Linux? -

It is because you have to use Mesa, which might be -running iin software. Mesa (http://www.mesa.org) -is an awesome package by Brian Paul (brianp@avid.com) which "emulates" -OpenGL. Basically, it is a fully compliant OpenGL package, but it -isn't officially sanctioned by the OpenGL ARB, such, it is doesn't have -the OpenGL name. There is an acceleration package for the many graphics -card, but I don't know anything about it. -
nVidia is being very supportive of Linux: -their TNT2 and GeForce cards work under Linux with hardware-acceleration of openGL. -(but the drivers are proprietary) -
radeon cards should also be supported very well under linux (even with open-source drivers) -

---- -
2.11) If I resize the window, everything looks strange. -

GEM doesn't trap resize events in IRIX or Linux (this -is not a problem in WinNT). This means that OpenGL doesn't have the -correct information to render properly. If you want to resize the -window, send a 'dimen x y' message to gemwin before you create the window. -

---- -
2.12) Can GEM run on a 3Dfx Voodoo card? -

I (this is: Mark Danks) have a Voodoo2 card, which runs fine under WinNT. -I use the OpenGL beta driver from 3Dfx at work all the time without any -problems and, except that the Voodoo takes over the full screen, it seems -to work fine. You will need to download the OpenGL Beta driver from -3Dfx's web site at http://www.3dfx.com and put the OpenGL32.dll into the -same directory as pd.exe (NOT gem.dll). Debugging patches is much -easier if you have two monitors, one for the 3-D card and one for the 2-D -card. -

IMPORTANT: You MUST set the environment variable -

GEM_SINGLE_CONTEXT = 1 -

to make the Voodoo card work. It will make a window 640x480 (which -is the correct size for TV video out on my Canopus V2 card). On WinNT, -right click "My Computer" and go to "Properties". On the "Environment" -tab, you need to add the variable "GEM_SINGLE_CONTEXT" with a value of -1. -
Resizing the GEM window with a Voodoo card is not -a great idea. The Voodoo card can only display certain window sizes and -will clip the graphics. -

For the tech heads in the audience...I create an -OpenGL context at startup and never actually display its associated window. -This means that GEM objects can create display lists, call OpenGL commands, -etc. in their constructors, even if no window is actually being displayed. -However, with the Voodoo card, there can only be one OpenGL context. -So, instead of creating one context and just holding onto it in the background, -I create the normal GEM window and associate the OpenGL context with it...and -the user can never destroy or close that window. -

---- -
2.13) Will GEM support hardware transform and lighting -(T & L)? -

Absolutely! Unlike some other APIs, OpenGL -will automatically use hardware accelerated transform and lighting if the -card has it. GEM gets great performance from cards like nVidia's -GeForce. -

2.14) I get an error "GEM needs Truecolor visual -support". -

This error means that your X display is running with -paletted colors, which is the result of limited color depth. If you -start the X display with -

startx -- -bpp 16 -

or some higher number, then it should work fine. 32-bit color -is the best. -

-

VIEWING OBJECTS

-
3.1)Why does everything seem dim?< -

You probably turned on lighting but don't have any -lights in the world. Either add a light with world_light or -light -or turn lighting off by sending a message 'lighting 0' to the gemwin. -You can also send a reset message to gemwin to set it back to the -startup state (which doesn't have any lighting). -

---- -
3.2) Why does everything seem dark? -

See question 3.1. -
If you are using view in your patch to change the viewpoint, -you may not be pointing in the correct direction. You also might have translated -everything outside of the current viewport. -
Also, if you have been using single buffering ('buffer -1' message to gemwin), then you might still be in that mode. -Either send a 'buffer 2' message or a 'reset' message to gemwin. -Then, destroy and create your window. -

-

TEXTURE MAPPING

-
4.1) My image doesn't appear. What is going -on? -

Normally images have to be texture-mapped onto Geos. -You have to use [pix_texture] to map the current image onto a Geo. -"Current" means that any pix-manipulation that is done after texturing will not be displayed. -

Any Geo has a color (which is initially set to white). -If you have set the color to black, your Geo (including the image) might be very dark. -If you are using alpha-blending, make sure that the Geo is not invisible. -

Normally images that want to be texture mapped with openGL should have dimensions that are a power of 2 in both height and width. -Now [pix_texture] will make this totally transparent to you (so normally you don't have to care about the size of the image). -However with non-power-of-2 images pix_coordinate might not behave as expected, -because these images need absolute texture-coordinates rather than normalized ones -(as are used with power-of-2 images): so if the texture-coordinates are set to "(0,0) (1,0) (1,1) (0,1)" you might see only the first pixel of the image (which might be black). -

Also, make sure that GEM can find your image (ie, -that the path name is correct). -

---- -
4.2) My image looks strange. What is going -on? -

GEM supports gray8, YUV, and RGBA images. If -it sees that the number of bits per channel and the number of channels -is something that it should be able to handle, it tries to load the raw -data. If you have compressed or stored the pixel data in some "strange" -format, then GEM will probably not read the information correctly. -
Also, if it is an RGBA image, then make sure that -the alpha channel is something useful (this only matters if you are using -the alpha channel, like in the alpha object or pix_mask). -

---- -
4.3) Why does GEM say that it can't handle a gray -image? -

This error message occurs whenever a pix object receives -a gray8 image and the implementor hasn't provided a way to deal with that -format of image. (Implementors often only provide functions for GEM's native -color-format RGBA. Any other color-format (like BGR) will try to call the function -for gray8 images, which might not be supported.) - If you do not want to change the image format with some extern image-programm -(like Photoshop or the Gimp) you might want to try pix_rgba -or harass whoever made the object to add the functionality. -

---- -
4.4) What image formats can GEM handle? -

GEM can read in TIFF, JPEG, and SGI images. -These can be in any color format. Gray scale images are loaded in -as gray scale (ie, one byte per pixel). Everything else is loaded -in or converted to an RGBA image (ie, four bytes per pixel). If there -is an alpha channel, then it will be respected. Otherwise, the alpha -channel will be set to fully opaque (alpha == 255). -

GEM can write TIFF and JPEG images. -TIFF-images will be full RGBA-images, wheras JPEG-files only support (compressed) RGB. -

---- -
4.5) What movie formats can GEM handle? -

The movie formats GEM can handle (still) depend on the platform -you are using. -

On Windoze you can read all AVI-files you have codecs for -

On linux the readable formats depend on the libraries you had installed when you compiled GEM. -Currently there is (optional) support for AVI, quicktime (*.MOV) and MPEG (*.MPG) files. -Not all quicktime-formats are supported. This is unfortunate but is due to linux restrictions. -I highly recommend that you install the mpeg3-library from Heroine because it is much more stable than mpeg1 (which comes with many linux-distributions). -If you have compiled in support for libavifile, you will be able to open Micro$oft-AVI-files. -If you have installed the proper codecs -(libavifile supports a mechanism for loading codecs from windows-DLLs) you should be able to -open almost any format. - -If you have serious problems, mail them to me. -(Be ready to upload the movie-file that won't work) -

---- -
4.6) Why is pix_draw so slow? -

pix_draw is almost never hardware accelerated -on PCs graphics accelerator. This means that it runs extremely -slowly. Always use pix_texture, even if you are just displaying -an image. -

-

WORKING WITH PD

-
5.1) Why do I get clicks in the audio? -

If you are getting a constant stream of clicks in -your audio, then it is probably because you are trying to do graphics and -audio in the same process. Rendering a graphics frame usually takes -longer than the size of the audio buffer, which is why you get clicks (the -clicks are usually at 20Hz...the typical frame rate). -
One way around this is to use two computers, one -for graphics and one for audio. If you have enough processing power -(or dual processors), then you can run two versions of Pd, one for graphics -and one for audio. Just use netsend and netreceive -to have the two versions of Pd talk to each other. -

---- -
5.2) How do I get audio data to GEM? -

One simple way to get raw audio values right now is -to use snapshot~. Just set up a metro which bangs snapshot~ -and use the floating point value. If you want "musical" information, -then use objects such as env~. -You might also have a look at the pix_sig2pix~ which interprets audio-data as pixels -and its counterpart pix_pix2sig~ -

---- -
5.3) Why can't GEM find an image/model file? -

This means that GEM can't locate the file. -If you use an absolute path (with / for instance), then GEM will look there. -Otherwise, GEM will look in the directory of where the patch is. -Then pd/GEM will search the paths you specified at startup with the -path flag. -

Check the following: -

1) Does the file exist? -
2) Did you make a typo in the filename? -
3) Is the file in the search-path ? -

---- -
5.4) How can I optimize my patches? -

One of the biggest performance hits is having UI -elements in your patch which have to be updated. The biggest performance -hog is the number box. While the number box is great for debugging, -make sure that they are all gone from your "release" patch. If you -run a performance meter, you will see that whenever Tcl/Tk has to update -the user interface, it sucks the entire processor. Another examples -of this is when you move a lot of objects at once, everything jerks and -slides across the screen. There are probably ways to improve this... -
Another problem is doing unneccessary calculations. -When you are throwing lots of numbers around, especially packing/unpacking, -doing vector math, etc., they add up. If the calculations are going -unused (for instance, that part of the patch is turned off), then do not -trigger the math objects. Use spigot or gate and block -the events early. This is especially important with objects that -send a lot of numbers, like ~ objects or line/tripleLine. -

-

WRITING NEW GEM OBJECTS

-
6.1) How do I write a new GEM object? -

For the time being, you have to look at the code. -It is fairly well documented and straight forward (if you know C++ and -OOP). Start with an object which is similar to what you want and -derive a new class. The biggest issue right now is how to load in -GEM as a DSO/DLL. For SGIs, you will need to setenv LD_LIBRARY_PATH. -On NT, you will need to have your path include the directory with GEM. -

---- -
6.2) What are the default OpenGL states? -

GemMan (and by association, gemwin) disables alpha -testing, alpha blending, culling, and lighting. Lighting defaults -to two sided, with GL_COLOR_MATERIAL enabled. The viewport is set -to -

float xDivy = (float)m_width / (float)m_height; -
glMatrixMode(GL_PROJECTION); -
glLoadIdentity(); -
glFrustum(-xDivy, xDivy, -1.0, 1.0, 1.0, 20.0); -
gluLookAt(0.0, 0.0, 4.0, 0.0, 0.0, 0.0, 0.0, 1.0, -0.0); -
glMatrixMode(GL_MODELVIEW); -
glViewport(0, 0, m_width, m_height); -

which gives a range of about -4 to 4 in X and Y at the origin. -This is a small range, but changing it now would break a lot of patches. -

The specific functions to look at are: -

GemMan::windowInit() -
GemMan::resetValues() -
gemhead::renderGL() -

-

OBJECT SPECIFIC

-
7.1) Why doesn't <object> exist on <platform>? -

Usually, this is because I don't have the resources -to get the object running on that platform. If an object that you -want doesn't exist on your platform, then ask for it! However, if -it is tied to hardware, then it is much less likely that I will be able -to do anything about it (unless someone donates the hardware to me...) -

---- -
7.2) Why doesn't gemtablet work? -

gemtablet only works on WinNT. I don't -have drivers for IRIX or Linux (also, see question 7.4) -
If GEM can find the tablet, then it will print a -message at window creation time. If you don't see a message, then -GEM doesn't think that you have a tablet. -
The tablet is mapped to the size of the GEM graphics -window. -

--- -
7.3) I don't want GEM to take over my tablet. -How do I stop it? -

Set the environment variable -

GEM_NO_TABLET = 1 -

---- -
7.4) Why doesn't gemmouse work in IRIX? -

Basically, I don't have physical access to an SGI machine. -This makes it hard to do some of the OS specific work. -It should be straightforward to do the event handling, so if someone gets -it working, I would love to include it (and give you credit). All -you have to do is call the correct event functions from GemEvent.h and -everything should just start to work (ie, gemmouse doesn't have any OS -specific code in it). -

---- -
7.5) Why doesn't gemorb work? -

You need to make sure that your SpaceOrb is hooked -up correctly. I am using a library which isn't supported by SpaceTec so -there can be problems, although I have not had any. -
<RANT> When will companies wake up and actually -provide drivers and support for their products under WinNT? </RANT> -

---- -
7.6) What is wrong with pix_video in WinNT? -

I haven't completely figured out how to get access -to the video stream in WinNT. I'm using Video for Windows with a -Connectix QuickCam, as well as an Intel Video Capture Card, and it seems -to assume that you are only writing to a file or previewing into a window. -Windows tries to take over the system and doesn't really provide any stable -hooks (unlike IRIX). If anyone knows how to deal with this, please -let me know. -

[return] -
-
- - + + + + + + + Gem FAQ + + + +

+

+GEM FAQ

+ +


* : new question +
+ : changed question +

+

+QUESTIONS

+GENERAL +
1.1) What is GEM? +
1.2) What is Pd? +
1.3) What platforms do GEM and Pd run on? +
1.4.0) How do I install GEM and Pd on IRIX? +
1.4.1) How do I install GEM and Pd on linux? +
1.4.2) How do I install GEM and Pd on WinNT? +
1.7) What is a good intro to OpenGL? +
1.8) Are there any web sites for Pd or GEM? +
1.9) What libraries does GEM use? (aka: Who does Mark +want to thank?) +
1.10) Are there any restrictions on GEM? +
1.11) How do I use GEM in a performance? +

USING GEM +
2.1) How do I (???) +
2.2) How do I make GEM run? +
2.3) Why doesn't GEM run? +
2.4) I've got it running. Now what? +
2.5) On IRIX 5.3, why does GEM dump with an rld error? +
2.6) Why can't I compile GEM on IRIX 5.3? +
2.7) Why is GEM slow in general? +
2.8) Why is GEM slow on IRIX? +
2.9) Why is GEM slow on WinNT/Win95? +
2.10) Why is GEM slow on Linux? +
2.11) If I resize the window, everything looks strange. +
2.12) Can GEM run on a 3Dfx Voodoo card? +
2.13) Will GEM support hardware transform and lighting +(T&L) ? +
2.14) I get an error "GEM needs Truecolor visual support". +

VIEWING OBJECTS +
3.1) Why does everything seem dim? +
3.2) Why does everything seem dark? +

TEXTURE MAPPING +
4.1) My image doesn't appear. What is going on? +
4.2) My image looks strange. What is going on? +
4.3) Why does GEM say that it can't handle a gray image? +
4.4) What image formats can GEM handle? +
4.5) What movie formats can GEM handle? +
4.6) Why is pix_draw so slow? +

WORKING WITH PD +
5.1) Why do I get clicks in the audio? +
5.2) How do I get audio data to GEM? +
5.3) Why can't GEM find an image/model file? +
5.4) How can I optimize my patches? +

WRITING NEW GEM OBJECTS +
6.1) How do I write a new GEM object? +
6.2) What are the default OpenGL states? +

OBJECT SPECIFIC +
7.1) Why doesn't <object> exist on <platform>? +
7.2) Why doesn't gemtablet work? +
7.3) I don't want GEM to take over my tablet. +How do I stop it? +
7.4) Why doesn't gemmouse work in IRIX/Linux? +
7.5) Why doesn't gemorb work? +
7.6) What is wrong with pix_video in WinNT? +

+

+ANSWERS

+

GENERAL

+
1.1) What is GEM? +

GEM is the Graphics Environment for Multimedia. +It was originally written by Mark Danks to generate real-time computer +graphics, especially for audio-visual compositions. It originally ran under +FTS/Max (which is why you might see some papers reference it), but all +new development is under Pd. +

You can get GEM at http://gem.iem.at/ +

GEM was sponsored by a grant from Intel (http://www.intel.com) +

GEM was ported to linux by Günter Geiger +

GEM is now maintained by IOhannes m zmölnig. +

the core-development team consists of

+lots of contributions are made by various people (thanks to all of them) +

---- +
1.2) What is Pd? +

Pd is a real-time environment for audio and MIDI. +It was written by Miller Puckette, who created FTS/Max when +he was at IRCAM. Basically, Pd can be seen as the next generation +of real-time visual programming languages. GEM runs inside of the +Pd environment. +

You can get Pd at http://www.crca.ucsd.edu/~msp/software.html +

Pd is sponsored by a grant from Intel (http://www.intel.com) +

---- +
1.3) What platforms do GEM and Pd run on? +

GEM and Pd run on Windows (95, 98, ME, NT 4.0, 2000, XP), linux and macOS-X (>10.2). +SGI-Irix (> 6.2) used to be supported but i don't have any prove that it still works). +Günter Geiger +has done an initial port of GEM and Pd to Linux http://gige.epy.co.at). +

GEM is now maintained by me and +developed by a team of several independent programmers (see section 1.1) +

---- +
1.4) How do I install GEM ? +

---- +
1.4.0) How do I install GEM and Pd on IRIX? +

See the readme for installing Pd. +

GEM should be at +

pd/gem +

If you run GEM.INSTALL.sh, then all of the example files and documention +should be put in the correct locations. +

---- +
1.4.1) How do I install GEM and Pd on linux? +

See the readme for installing Pd. +

GEM should be at +

chdir to <gem>/src/Gnu and build Gem following the instructions in the README.build +(./configure; make) +

If you then make install, then all of the example files and documention +should be put in the correct locations. +

if you are using debian, Gem should be available via apt

+

if you are using an rpm-based distribution, check out the builds at planetCCRMA

+

---- +
1.4.2) How do I install GEM and Pd on WinNT? +

See the readme for installing Pd. +

unzip GEM so that it is at +

pd\gem +

If you run GEM.INSTALL.bat, then all of the example files and documentation +should be put in the correct locations. +

there is also an installer for windows. +

---- +
1.4.3) How do I install GEM and Pd on macOS? +

See the readme for installing Pd. +

there is also an installer for macOS. +

---- +
1.7) What is a good intro to OpenGL? +

The best book is the OpenGL Programming Manual +by Mason and Woo. This is also called the "Red Book". If you search +the web, there are many sites on OpenGL. A good starting point is +http://www.opengl.org. +Also, Mark Kilgard (who used to work for SGI) has a wonderful site with +lots of links (http://reality.sgi.com/mjk) +Also, Normal Lin has written another great book on 3D-graphics under linux +

---- +
1.8) Are there any web sites for Pd or GEM? +

Except for the ones noted above, there is the Japanese +installation page at +
http://www.rinc.or.jp/~kotobuki/gem/index.htm +

There is a Pd mailing list. Subscription info +is on IEM's site http://www.iem.at/mailinglists/pd-list +

One of pd's unofficial home-pages is at http://pd.iem.at hosted by the +Institute of Electronic Music and Acoustics, Graz, Austria +

Also hosted by the iem is the site of the pd-community +http://www.puredata.info +

An interesting place might also be Günter Geiger's size http://gige.epy.co.at/ +

there are lot's of other cool pages (search the net...) +

---- +
1.9) What libraries does GEM use? +(aka: Who does Mark want to thank?) +

All copyrights and license info can be found in +
GEM.LICENSE.TERMS +
Thanks to Sam Leffner for libTiff, the TIFF image +loader. +
+sam@engr.sgi.com +
ftp://ftp.sgi.com/graphics/tiff/ +
Thanks to Masayuki Matsumoto for fstimage for OpenGL, +the SGI +
image loader. +
+matumot@dst.nk-exa.co.jp +
Thanks to the Independent JPEG Group for libjpeg, +the JPEG image loader. +
+jpeg-info@uunet.uu.net +
ftp://ftp.simtel.net/pub/simtelnet/msdos/graphics/ +
Thanks to Mark Kilgard at al. (and SGI) for glut, the openGL Utility Toolkit +
http://www.pobox.com/~ndr +
Thanks to Stephane Rehel for GLTT, the OpenGL TrueType +render. +
+rehel@worldnet.fr +
http://home.worldnet.fr/~rehel/gltt/gltt.html +
Thanks to David Turner, Robert Wilhelm, and Werner +Lemberg for +
Freetype, a TrueType font +rendering engine. +
+turner@enst.fr +
+robert@physiol.med.tu-muenchen.de +
+a7971428@unet.univie.ac.at +
http://www.physiol.med.tu-muenchen.de/~robert/freetype.html +
Thanks to the MPEG Software Simulation Group, for +libmpeg, the +
MPEG-2 Encoder/Decoder +
+mssg@mpeg.org +
http://www.mpeg.org/MSSG/ +
Thanks to Heroine for quicktime4linux +a quickime Decoder +and libmpeg3, another MPEG-2 Encoder/Decoder +
MPEG-2 Encoder/Decoder +
+mssg@mpeg.org +
http://heroinewarrior.com/ +
Thanks to LCS/Telegraphics for Wintab, the Windows +tablet library. +
+wintab@pointing.com +
Thanks to David McAllister for the Particle System +library. +
+davemc@cs.unc.edu +
http://www.cs.unc.edu/~davemc/Particle/ +
Thanks to John Stone for the Space Orb library, +libOrb +
+j.stone@acm.org +
http://www.umr.edu/~johns/projects/liborb/ +

---- +
1.10) Are there any restrictions on GEM? +

GEM is under the Gnu Public License. This basically +means that it will always be free software.Check out http://www.gnu.org +for more information and read the full license in GnuGPL.LICENSE in the GEM release. +

---- +
1.11) How do I use GEM in a performance? +

This is a constant problem, because there is no consistent +way to display video on any platform. Also, you usually do not want +to send the entire screen, but only the GEM window. It is also useful +to be able to edit/control the Pd patch window while the patch is actually +running. +

On SGIs, the best way is to get a video out option. +On the SGI O2, Impact, and Onyx (Mark has used all of these), there is a +simple connector or breakout box to do video. +If you run the video out program, then you will get a rectangle on your screen +which shows what is being sent out the video connector. +Make your GEM window a little larger than 640x480 and center it in the rectangle. +You can now project this with a standard video projector. +

On PCs it is a bit harder. +Several modern video-cards have the possibility to output several screens +(either 2 (or more) VGA-screens or 1 VGA-screen and 1 TV (Composite or S-HVS) +or a combination with DFTs) +If you have a Canopus Voodoo2 card it has a video and s-video output on it. As described +in question 2.12, you can get a Voodoo to work with +GEM. If any one else has a better solution, please let me know. +The nVidia Riva TNTs require that you output the full screen, so this is +not a very good option. You can use a video scan convertor. +Some of them only display a part of the scene, which is exactly what you +want. +

With modern multi-headed cards it is more simple: +Configure your card to display the desktop spread over your multiple screens +(e.g.: from left-to-right). +On windows and macOS you can do this via the display-properties dialog. +On linux you will have to edit your /etc/X11/XF86Config-4 file either by hand or +(if your system supports it) via an appropriate editor (yes, nowadays there are some). +Now create your gem-window on the second screen: +it should have the same dimensions as the 2nd screen (e.g: "[dimen 800 600("). +to place it at the second screen use the offset (e.g: if your primary sreen +(the one you want for patch-editing) has the dimension 1024x768 use "[offset 1024 0(", +which will create the gem-window 1024 pixels right of the upper-left corner +of the total screen (and 0 pixels below it), +which is exactly the upper-left corner of the 2nd screen. +You most probably want to turn off the borders with "[border 0(".
+Note: some grafix-card have openGL-hardware-acceleration only on the 1st screen +(so you should create the gem-window on the 1st screen and move +your patches to the 2nd screen) +

If you are using an XServer for displaying (under linux) you can also use another +computer for rendering. +You can specify the place where the gem-window should be created with something like +"create <render.host>:0.0" + +

If you are doing audio with graphics, the only solution +to prevent clicking (question 5.1) is to run 2 computers +and have them communicate with netsend/netreceive. We are working +on making Pd/GEM multi-processor friendly, so if you have a multi-processor +system, you can run everything on one machine eventually. +

+

USING GEM

+
2.1)How do I (???) +

Many of the general usage questions are probably +answered in the manual or release notes. The pd mailing list is also +a good place to find answers as well. +

2.2) How do I make GEM run? +

GEM is not an executable. It requires Pd to +work and is loaded in at run time. For example, I have an alias on +the SGI which does +

/usr/people/mdanks/pd/bin/pd -lib /usr/people/mdanks/pd/gem/Gem +

and on WinNT +

\pdDir\pd\bin\pd -lib /pdDir/pd/gem/Gem +

on UNIX-systems you will probably want to use a .pdrc file, + where you can put the command-line arguments for pd that you "always" need. +

If you don't see a startup message from GEM, then something went wrong. +

Most people use use the command shell to start Pd. +It is not very difficult to configure Pd to run from double-clicking on the icon. +

---- +
2.3) Why doesn't GEM run? +

Notice that the -lib flag always requires Unix +styles slashes. This is the case even on Windows. +

You may also want to use the -nosound flag. +For instance, my PC has problems using audio (it leaks memory), so I just +turn off the audio part of Pd. However, other people can't get GEM +to work if the -nosound is used (on Win95). You can also try the +-dac or -adc flags (for digital-analog-conversion only and analog-digital-conversion +only). +

---- +
2.4) I've got it running. Now what? +

Try out the manual. It will step you through +the basics. +
You will also want to look at the example files. +Assuming that everything is installed correctly, you can get to the examples +by going to the Help menu in Pd and selecting examples. A bunch of +the patches should start with gem<something>. The best one is +gem/01.basic/01.redSquare.pd +It puts a red square up on the screen and allows you to rotate it. gemImage.pd +shows how to load in a TIFF file. gem/03.lighting/04.moveSpheres.pd +moves two spheres around the screen. Try the other ones. +
Most of the GEM objects have test patches which +give some information about the various controls for the object. +

---- +
2.5) On IRIX 5.3, why does GEM dump with an rld error? +

GEM only works under IRIX 6.2+. The rld error +is probably something about not having glBindTextureEXT (or something). +OpenGL 1.0 has some extensions to speed up texture mapping (which are an +integral part of OpenGL 1.1). However, these don't exist on IRIX +5.3. If you recompile GEM (see the next question), things should +work fine. +
I don't have access to an IRIX machine, so don't +expect any builds from me. Upgrading to IRIX 6.2+ is worth it. +

---- +
2.6) Why can't I compile GEM on IRIX 5.3? +

There was probably an error saying that the compiler +couldn't find the file "dmedia/vl_vino.h" in pix_videoSGI.cpp. IRIX +6.2+ adds new functionality to the media libraries which makes life much +easier. You cannot compile pix_video or pix_indycam as is under 5.3. +You can remove them from the Pix/Makefile and from the linker part of the +global Makefile. You will also need to recompile the Td and Tiff +libraries. +

There shouldn't be any problems doing this. I haven't tried any +of this, so if it works for someone, please let me know. +

---- +
2.7) Why is GEM slow in general? +

Examine what you are doing. If you are constantly +changing textures, then this is probably your problem. If you have +models with a million triangles, then this is probably the problem. +Compare what you are doing with realistic specs on your system. Some +systems slow down when they have to draw very large polygons (slow fill +rate). +
You can also turn on profiling to see how long it +takes to render a frame. Send a profile message to the gemwin object. +The number that is printed is the number of milliseconds one frame takes +to render. 50 milliseconds is 20 frames per second. 'profile 2' is +good if you want to see how long the image processing is taking. +
profile 0 - turn off profiling +
profile 1 - turn on profiling +
profile 2 - turn on profiling +and don't cache pixes +

---- +
2.8) Why is GEM slow on IRIX? +

If you are having major slowdowns, then please let +me know. I have gotten very good performance on most machines (Indy, +O2, Impact, Onyx2). +

---- +
2.9) Why is GEM slow on WinNT/Win95? +

You probably don't have hardware acceleration. +You can use software rendering, but it basically useless except for extremely +basic patches. You can get a good graphics accelerator for really +cheap these days. I recommend a card based on nVidia's chipsets, +such as the TNT2 or GeForce, but there are other companies such as 3dfx +and Matrox. Make sure that you are running the latest drivers for +your card. The basic drivers that come with the cards are usually +very bad. +
Also, PCs don't deal with lots of texture maps very +well (they are bus limited, at least until AGP), so if you are trying to +use lots of constantly changing texture maps +(especially with [pix_multiimage], [pix_video] or [pix_film]), that will cause problems. +

---- +
2.10) Why is GEM slow on Linux? +

It is because you have to use Mesa, which might be +running iin software. Mesa (http://www.mesa.org) +is an awesome package by Brian Paul (brianp@avid.com) which "emulates" +OpenGL. Basically, it is a fully compliant OpenGL package, but it +isn't officially sanctioned by the OpenGL ARB, such, it is doesn't have +the OpenGL name. There is an acceleration package for the many graphics +card, but I don't know anything about it. +
nVidia is being very supportive of Linux: +their TNT2 and GeForce cards work under Linux with hardware-acceleration of openGL. +(but the drivers are proprietary) +
radeon cards should also be supported very well under linux (even with open-source drivers) +

---- +
2.11) If I resize the window, everything looks strange. +

GEM doesn't trap resize events in IRIX or Linux (this +is not a problem in WinNT). This means that OpenGL doesn't have the +correct information to render properly. If you want to resize the +window, send a 'dimen x y' message to gemwin before you create the window. +

---- +
2.12) Can GEM run on a 3Dfx Voodoo card? +

I (this is: Mark Danks) have a Voodoo2 card, which runs fine under WinNT. +I use the OpenGL beta driver from 3Dfx at work all the time without any +problems and, except that the Voodoo takes over the full screen, it seems +to work fine. You will need to download the OpenGL Beta driver from +3Dfx's web site at http://www.3dfx.com and put the OpenGL32.dll into the +same directory as pd.exe (NOT gem.dll). Debugging patches is much +easier if you have two monitors, one for the 3-D card and one for the 2-D +card. +

IMPORTANT: You MUST set the environment variable +

GEM_SINGLE_CONTEXT = 1 +

to make the Voodoo card work. It will make a window 640x480 (which +is the correct size for TV video out on my Canopus V2 card). On WinNT, +right click "My Computer" and go to "Properties". On the "Environment" +tab, you need to add the variable "GEM_SINGLE_CONTEXT" with a value of +1. +
Resizing the GEM window with a Voodoo card is not +a great idea. The Voodoo card can only display certain window sizes and +will clip the graphics. +

For the tech heads in the audience...I create an +OpenGL context at startup and never actually display its associated window. +This means that GEM objects can create display lists, call OpenGL commands, +etc. in their constructors, even if no window is actually being displayed. +However, with the Voodoo card, there can only be one OpenGL context. +So, instead of creating one context and just holding onto it in the background, +I create the normal GEM window and associate the OpenGL context with it...and +the user can never destroy or close that window. +

---- +
2.13) Will GEM support hardware transform and lighting +(T & L)? +

Absolutely! Unlike some other APIs, OpenGL +will automatically use hardware accelerated transform and lighting if the +card has it. GEM gets great performance from cards like nVidia's +GeForce. +

2.14) I get an error "GEM needs Truecolor visual +support". +

This error means that your X display is running with +paletted colors, which is the result of limited color depth. If you +start the X display with +

startx -- -bpp 16 +

or some higher number, then it should work fine. 32-bit color +is the best. +

+

VIEWING OBJECTS

+
3.1)Why does everything seem dim?< +

You probably turned on lighting but don't have any +lights in the world. Either add a light with world_light or +light +or turn lighting off by sending a message 'lighting 0' to the gemwin. +You can also send a reset message to gemwin to set it back to the +startup state (which doesn't have any lighting). +

---- +
3.2) Why does everything seem dark? +

See question 3.1. +
If you are using view in your patch to change the viewpoint, +you may not be pointing in the correct direction. You also might have translated +everything outside of the current viewport. +
Also, if you have been using single buffering ('buffer +1' message to gemwin), then you might still be in that mode. +Either send a 'buffer 2' message or a 'reset' message to gemwin. +Then, destroy and create your window. +

+

TEXTURE MAPPING

+
4.1) My image doesn't appear. What is going +on? +

Normally images have to be texture-mapped onto Geos. +You have to use [pix_texture] to map the current image onto a Geo. +"Current" means that any pix-manipulation that is done after texturing will not be displayed. +

Any Geo has a color (which is initially set to white). +If you have set the color to black, your Geo (including the image) might be very dark. +If you are using alpha-blending, make sure that the Geo is not invisible. +

Normally images that want to be texture mapped with openGL should have dimensions that are a power of 2 in both height and width. +Now [pix_texture] will make this totally transparent to you (so normally you don't have to care about the size of the image). +However with non-power-of-2 images pix_coordinate might not behave as expected, +because these images need absolute texture-coordinates rather than normalized ones +(as are used with power-of-2 images): so if the texture-coordinates are set to "(0,0) (1,0) (1,1) (0,1)" you might see only the first pixel of the image (which might be black). +

Also, make sure that GEM can find your image (ie, +that the path name is correct). +

---- +
4.2) My image looks strange. What is going +on? +

GEM supports gray8, YUV, and RGBA images. If +it sees that the number of bits per channel and the number of channels +is something that it should be able to handle, it tries to load the raw +data. If you have compressed or stored the pixel data in some "strange" +format, then GEM will probably not read the information correctly. +
Also, if it is an RGBA image, then make sure that +the alpha channel is something useful (this only matters if you are using +the alpha channel, like in the alpha object or pix_mask). +

---- +
4.3) Why does GEM say that it can't handle a gray +image? +

This error message occurs whenever a pix object receives +a gray8 image and the implementor hasn't provided a way to deal with that +format of image. (Implementors often only provide functions for GEM's native +color-format RGBA. Any other color-format (like BGR) will try to call the function +for gray8 images, which might not be supported.) + If you do not want to change the image format with some extern image-programm +(like Photoshop or the Gimp) you might want to try pix_rgba +or harass whoever made the object to add the functionality. +

---- +
4.4) What image formats can GEM handle? +

GEM can read in TIFF, JPEG, and SGI images. +These can be in any color format. Gray scale images are loaded in +as gray scale (ie, one byte per pixel). Everything else is loaded +in or converted to an RGBA image (ie, four bytes per pixel). If there +is an alpha channel, then it will be respected. Otherwise, the alpha +channel will be set to fully opaque (alpha == 255). +

GEM can write TIFF and JPEG images. +TIFF-images will be full RGBA-images, wheras JPEG-files only support (compressed) RGB. +

---- +
4.5) What movie formats can GEM handle? +

The movie formats GEM can handle (still) depend on the platform +you are using. +

On Windoze you can read all AVI-files you have codecs for +

On linux the readable formats depend on the libraries you had installed when you compiled GEM. +Currently there is (optional) support for AVI, quicktime (*.MOV) and MPEG (*.MPG) files. +Not all quicktime-formats are supported. This is unfortunate but is due to linux restrictions. +I highly recommend that you install the mpeg3-library from Heroine because it is much more stable than mpeg1 (which comes with many linux-distributions). +If you have compiled in support for libavifile, you will be able to open Micro$oft-AVI-files. +If you have installed the proper codecs +(libavifile supports a mechanism for loading codecs from windows-DLLs) you should be able to +open almost any format. + +If you have serious problems, mail them to me. +(Be ready to upload the movie-file that won't work) +

---- +
4.6) Why is pix_draw so slow? +

pix_draw is almost never hardware accelerated +on PCs graphics accelerator. This means that it runs extremely +slowly. Always use pix_texture, even if you are just displaying +an image. +

+

WORKING WITH PD

+
5.1) Why do I get clicks in the audio? +

If you are getting a constant stream of clicks in +your audio, then it is probably because you are trying to do graphics and +audio in the same process. Rendering a graphics frame usually takes +longer than the size of the audio buffer, which is why you get clicks (the +clicks are usually at 20Hz...the typical frame rate). +
One way around this is to use two computers, one +for graphics and one for audio. If you have enough processing power +(or dual processors), then you can run two versions of Pd, one for graphics +and one for audio. Just use netsend and netreceive +to have the two versions of Pd talk to each other. +

---- +
5.2) How do I get audio data to GEM? +

One simple way to get raw audio values right now is +to use snapshot~. Just set up a metro which bangs snapshot~ +and use the floating point value. If you want "musical" information, +then use objects such as env~. +You might also have a look at the pix_sig2pix~ which interprets audio-data as pixels +and its counterpart pix_pix2sig~ +

---- +
5.3) Why can't GEM find an image/model file? +

This means that GEM can't locate the file. +If you use an absolute path (with / for instance), then GEM will look there. +Otherwise, GEM will look in the directory of where the patch is. +Then pd/GEM will search the paths you specified at startup with the -path flag. +

Check the following: +

1) Does the file exist? +
2) Did you make a typo in the filename? +
3) Is the file in the search-path ? +

---- +
5.4) How can I optimize my patches? +

One of the biggest performance hits is having UI +elements in your patch which have to be updated. The biggest performance +hog is the number box. While the number box is great for debugging, +make sure that they are all gone from your "release" patch. If you +run a performance meter, you will see that whenever Tcl/Tk has to update +the user interface, it sucks the entire processor. Another examples +of this is when you move a lot of objects at once, everything jerks and +slides across the screen. There are probably ways to improve this... +
Another problem is doing unneccessary calculations. +When you are throwing lots of numbers around, especially packing/unpacking, +doing vector math, etc., they add up. If the calculations are going +unused (for instance, that part of the patch is turned off), then do not +trigger the math objects. Use spigot or gate and block +the events early. This is especially important with objects that +send a lot of numbers, like ~ objects or line/tripleLine. +

+

WRITING NEW GEM OBJECTS

+
6.1) How do I write a new GEM object? +

For the time being, you have to look at the code. +It is fairly well documented and straight forward (if you know C++ and +OOP). Start with an object which is similar to what you want and +derive a new class. The biggest issue right now is how to load in +GEM as a DSO/DLL. For SGIs, you will need to setenv LD_LIBRARY_PATH. +On NT, you will need to have your path include the directory with GEM. +

---- +
6.2) What are the default OpenGL states? +

GemMan (and by association, gemwin) disables alpha +testing, alpha blending, culling, and lighting. Lighting defaults +to two sided, with GL_COLOR_MATERIAL enabled. The viewport is set +to +

float xDivy = (float)m_width / (float)m_height; +
glMatrixMode(GL_PROJECTION); +
glLoadIdentity(); +
glFrustum(-xDivy, xDivy, -1.0, 1.0, 1.0, 20.0); +
gluLookAt(0.0, 0.0, 4.0, 0.0, 0.0, 0.0, 0.0, 1.0, +0.0); +
glMatrixMode(GL_MODELVIEW); +
glViewport(0, 0, m_width, m_height); +

which gives a range of about -4 to 4 in X and Y at the origin. +This is a small range, but changing it now would break a lot of patches. +

The specific functions to look at are: +

GemMan::windowInit() +
GemMan::resetValues() +
gemhead::renderGL() +

+

OBJECT SPECIFIC

+
7.1) Why doesn't <object> exist on <platform>? +

Usually, this is because I don't have the resources +to get the object running on that platform. If an object that you +want doesn't exist on your platform, then ask for it! However, if +it is tied to hardware, then it is much less likely that I will be able +to do anything about it (unless someone donates the hardware to me...) +

---- +
7.2) Why doesn't gemtablet work? +

gemtablet only works on WinNT. I don't +have drivers for IRIX or Linux (also, see question 7.4) +
If GEM can find the tablet, then it will print a +message at window creation time. If you don't see a message, then +GEM doesn't think that you have a tablet. +
The tablet is mapped to the size of the GEM graphics +window. +

--- +
7.3) I don't want GEM to take over my tablet. +How do I stop it? +

Set the environment variable +

GEM_NO_TABLET = 1 +

---- +
7.4) Why doesn't gemmouse work in IRIX? +

Basically, I don't have physical access to an SGI machine. +This makes it hard to do some of the OS specific work. +It should be straightforward to do the event handling, so if someone gets +it working, I would love to include it (and give you credit). All +you have to do is call the correct event functions from GemEvent.h and +everything should just start to work (ie, gemmouse doesn't have any OS +specific code in it). +

---- +
7.5) Why doesn't gemorb work? +

You need to make sure that your SpaceOrb is hooked +up correctly. I am using a library which isn't supported by SpaceTec so +there can be problems, although I have not had any. +
<RANT> When will companies wake up and actually +provide drivers and support for their products under WinNT? </RANT> +

---- +
7.6) What is wrong with pix_video in WinNT? +

I haven't completely figured out how to get access +to the video stream in WinNT. I'm using Video for Windows with a +Connectix QuickCam, as well as an Intel Video Capture Card, and it seems +to assume that you are only writing to a file or previewing into a window. +Windows tries to take over the system and doesn't really provide any stable +hooks (unlike IRIX). If anyone knows how to deal with this, please +let me know. +

[return] +
+
+ + diff --git a/Gem/manual/GemWPd.html b/Gem/manual/GemWPd.html index b564d99..46c863a 100644 --- a/Gem/manual/GemWPd.html +++ b/Gem/manual/GemWPd.html @@ -1,140 +1,140 @@ - - - - - - - Using GEM with Pd - - - -

-

-Using GEM with Pd

-    An important fact is that GEM is NOT an application. -It is a library that the application Pd loads in at run-time.  Most -of this information is taken directly from the GEM FAQ. -

How do I install GEM on IRIX? -
How do I install GEM on Win95/NT/2k? -
How do I install GEM on linux? -
How do I install GEM on macOS-X? -
How do I run GEM on IRIX? -
How do I run GEM on Win95/NT/2k? -
How do I run GEM on linux? -
How do I run GEM on linux? -
Why doesn't GEM run? -

-

-How do I install GEM and Pd on IRIX?

-See the readme for installing Pd. -

Uncompress and untar the GEM file that you downloaded.  GEM should -be located at -

pd/gem -

depending on where you have installed Pd. -

If you run the shell script, GEM.INSTALL.sh, then all of the example -files and documention -
should be put in the correct locations. -

-

-How do I install GEM and Pd on WinNT?

-See the readme for installing Pd. -

TODO: there should be a install package somewhere -

Unzip the GEM file that you downloaded so that it is at -

pd\gem -

depending on where you have installed Pd. -

If you run GEM.INSTALL.bat, then all of the example files and documentation -should be put in the correct locations. -

-

-How do I install GEM and Pd on linux?

-See the readme for installing Pd. -

Uncompress and untar the GEM file that you downloaded so that it is at -

pd/gem -

depending on where you have installed Pd. -

chdir into <pd/gem>/src/Gnu -

read the README.build -

run ./configure and afterwards make -

If you run make install, then all of the example files and documentation -should be put in the correct locations. -

-

-How do I install GEM and Pd on macOS-X?

-See the readme for installing Pd. -

TODO: there should be a install package somewhere -

-

-How do I run GEM on IRIX?

-   To use GEM type something like: -

/usr/people/mdanks/pd/bin/pd -lib /usr/people/mdanks/pd/gem/Gem -

(where /usr/people/mdanks is the path to the pd directory). Check out -the README for Pd to see examples of the -lib flag. If you just try to -"run" GEM, you will get an error! Notice that last word is a capital Gem. -If you get a "can't find gem_setup" error, then that is the problem. Look -in the GEM FAQ -
for trouble shooting suggestions. -

If you don't see startup messages from GEM, then something went wrong. -
Also, you might need to add pd/bin to your PATH environment variable. -

-

-How do I run GEM on Win95/NT?

-    It is best to start Pd from a DOS command line.  -If you go to the Start menu, you should find an application called "Command -Prompt" under the Program menu.  You need to change to the drive where -you installed Pd.  For instance, if it is on your D: drive, just type -d: at the prompt. -

   To use GEM type something like: -

\pd\bin\pd -lib /pd/gem/Gem -

depending on where you installed Pd. -

    Check out the README for Pd to see examples of the --lib flag. If you just try to double click GEM, you will get an error! -Notice that last word is a capital Gem. If you get a "can't find gem_setup" -error, then that is the problem. Look in the GEM FAQ for trouble shooting -suggestions. -

If you don't see a startup message from GEM, then something went wrong. -

    Most people use the command shell to start Pd.  -It is difficult to configure Pd to run from double-clicking on the icon. -

    Also, you might need to add pd/bin to your PATH environment -variable. -

-

-How do I run GEM on linux?

-   To use GEM type something like: -

/usr/people/mdanks/pd/bin/pd -lib /usr/people/mdanks/pd/gem/Gem -

(where /usr/people/mdanks is the path to the pd directory). Check out -the README for Pd to see examples of the -lib flag. If you just try to -"run" GEM, you will get an error! Notice that last word is a capital Gem. -If you get a "can't find gem_setup" error, then that is the problem. Look -in the GEM FAQ -
for trouble shooting suggestions. -

If you don't see startup messages from GEM, then something went wrong. -
Also, you might need to add pd/bin to your PATH environment variable. -

-

-How do I run GEM on macOS-X?

-   To use GEM type something like: -/usr/local/bin/pd -lib /Users/zmoelnig/pd/Gem -

(where /usr/local/bin/pd is the path to the pd directory and -/Users/zmoelnig/pd is the path where the Gem.pd_darwin resides). -Check out the README for Pd to see examples of the -lib flag. If you just try to -"run" GEM, you will get an error! Notice that last word is a capital Gem. -If you get a "can't find gem_setup" error, then that is the problem. Look -in the GEM FAQ -
for trouble shooting suggestions. -

If you don't see startup messages from GEM, then something went wrong. -
Also, you might need to add pd/bin to your PATH environment variable. -

-

-Why doesn't GEM run?

-    Notice that the -lib flag always requires Unix styles -slashes, even if you are on Windows.  This means that you need to -do -lib /gem/Gem, not -lib \gem\Gem -

    You may also want to use the -nosound flag.  -For instance, my PC has problems using audio (it leaks memory), so I just -turn off the audio part of Pd.  However, other people can't get GEM -to work if the -nosound is used (on Win95).  You can also try the --dac or -adc flags (for digital-analog-conversion only and analog-digital-conversion -only). -

[return] -
  - - + + + + + + + Using GEM with Pd + + + +

+

+Using GEM with Pd

+    An important fact is that GEM is NOT an application. +It is a library that the application Pd loads in at run-time.  Most +of this information is taken directly from the GEM FAQ. +

How do I install GEM on IRIX? +
How do I install GEM on Win95/NT/2k? +
How do I install GEM on linux? +
How do I install GEM on macOS-X? +
How do I run GEM on IRIX? +
How do I run GEM on Win95/NT/2k? +
How do I run GEM on linux? +
How do I run GEM on linux? +
Why doesn't GEM run? +

+

+How do I install GEM and Pd on IRIX?

+See the readme for installing Pd. +

Uncompress and untar the GEM file that you downloaded.  GEM should +be located at +

pd/gem +

depending on where you have installed Pd. +

If you run the shell script, GEM.INSTALL.sh, then all of the example +files and documention +
should be put in the correct locations. +

+

+How do I install GEM and Pd on WinNT?

+See the readme for installing Pd. +

TODO: there should be a install package somewhere +

Unzip the GEM file that you downloaded so that it is at +

pd\gem +

depending on where you have installed Pd. +

If you run GEM.INSTALL.bat, then all of the example files and documentation +should be put in the correct locations. +

+

+How do I install GEM and Pd on linux?

+See the readme for installing Pd. +

Uncompress and untar the GEM file that you downloaded so that it is at +

pd/gem +

depending on where you have installed Pd. +

chdir into <pd/gem>/src/Gnu +

read the README.build +

run ./configure and afterwards make +

If you run make install, then all of the example files and documentation +should be put in the correct locations. +

+

+How do I install GEM and Pd on macOS-X?

+See the readme for installing Pd. +

TODO: there should be a install package somewhere +

+

+How do I run GEM on IRIX?

+   To use GEM type something like: +

/usr/people/mdanks/pd/bin/pd -lib /usr/people/mdanks/pd/gem/Gem +

(where /usr/people/mdanks is the path to the pd directory). Check out +the README for Pd to see examples of the -lib flag. If you just try to +"run" GEM, you will get an error! Notice that last word is a capital Gem. +If you get a "can't find gem_setup" error, then that is the problem. Look +in the GEM FAQ +
for trouble shooting suggestions. +

If you don't see startup messages from GEM, then something went wrong. +
Also, you might need to add pd/bin to your PATH environment variable. +

+

+How do I run GEM on Win95/NT?

+    It is best to start Pd from a DOS command line.  +If you go to the Start menu, you should find an application called "Command +Prompt" under the Program menu.  You need to change to the drive where +you installed Pd.  For instance, if it is on your D: drive, just type +d: at the prompt. +

   To use GEM type something like: +

\pd\bin\pd -lib /pd/gem/Gem +

depending on where you installed Pd. +

    Check out the README for Pd to see examples of the +-lib flag. If you just try to double click GEM, you will get an error! +Notice that last word is a capital Gem. If you get a "can't find gem_setup" +error, then that is the problem. Look in the GEM FAQ for trouble shooting +suggestions. +

If you don't see a startup message from GEM, then something went wrong. +

    Most people use the command shell to start Pd.  +It is difficult to configure Pd to run from double-clicking on the icon. +

    Also, you might need to add pd/bin to your PATH environment +variable. +

+

+How do I run GEM on linux?

+   To use GEM type something like: +

/usr/people/mdanks/pd/bin/pd -lib /usr/people/mdanks/pd/gem/Gem +

(where /usr/people/mdanks is the path to the pd directory). Check out +the README for Pd to see examples of the -lib flag. If you just try to +"run" GEM, you will get an error! Notice that last word is a capital Gem. +If you get a "can't find gem_setup" error, then that is the problem. Look +in the GEM FAQ +
for trouble shooting suggestions. +

If you don't see startup messages from GEM, then something went wrong. +
Also, you might need to add pd/bin to your PATH environment variable. +

+

+How do I run GEM on macOS-X?

+   To use GEM type something like: +/usr/local/bin/pd -lib /Users/zmoelnig/pd/Gem +

(where /usr/local/bin/pd is the path to the pd directory and +/Users/zmoelnig/pd is the path where the Gem.pd_darwin resides). +Check out the README for Pd to see examples of the -lib flag. If you just try to +"run" GEM, you will get an error! Notice that last word is a capital Gem. +If you get a "can't find gem_setup" error, then that is the problem. Look +in the GEM FAQ +
for trouble shooting suggestions. +

If you don't see startup messages from GEM, then something went wrong. +
Also, you might need to add pd/bin to your PATH environment variable. +

+

+Why doesn't GEM run?

+    Notice that the -lib flag always requires Unix styles +slashes, even if you are on Windows.  This means that you need to +do -lib /gem/Gem, not -lib \gem\Gem +

    You may also want to use the -nosound flag.  +For instance, my PC has problems using audio (it leaks memory), so I just +turn off the audio part of Pd.  However, other people can't get GEM +to work if the -nosound is used (on Win95).  You can also try the +-dac or -adc flags (for digital-analog-conversion only and analog-digital-conversion +only). +

[return] +
  + + diff --git a/Gem/manual/Gloss.html b/Gem/manual/Gloss.html index 1d42709..fcf35c9 100644 --- a/Gem/manual/Gloss.html +++ b/Gem/manual/Gloss.html @@ -1,41 +1,41 @@ - - - - - - - Glossary/Index - - - -

-

-Glossary

-Alpha - The amount of opacity.  An alpha equal -to 1.0 means completely opaque.  An alpha equal to 0.0 means completely -transparent. -

Controls - GEM objects which access the low levels -of GEM, such as window managers. -

Geos - GEM objects which have a shape of some kind, -such as a cube. -

Manips - GEM objects which manipulate the geos. -

MarkEx - A collection of objects which help with -data manipulation, especially for usage in GEM. -

Nongeos - GEM objects which do not have an explicit -shape, yet affect the rendering in some way. -

OpenGL - A -graphics API which exists on many different platforms.
-Gem can also be used as a wrapper for openGL, allowing to program openGL without having to -compile -

Particles - GEM objects which involve the particle -system. -

Pd -- A visual programming language for audio processing.  This is the -host application for GEM. -

Pixes - Image processing objects in GEM -

Texture mapping - Applying an image to a geometric -object. -

[return] -
  - - + + + + + + + Glossary/Index + + + +

+

+Glossary

+Alpha - The amount of opacity.  An alpha equal +to 1.0 means completely opaque.  An alpha equal to 0.0 means completely +transparent. +

Controls - GEM objects which access the low levels +of GEM, such as window managers. +

Geos - GEM objects which have a shape of some kind, +such as a cube. +

Manips - GEM objects which manipulate the geos. +

MarkEx - A collection of objects which help with +data manipulation, especially for usage in GEM. +

Nongeos - GEM objects which do not have an explicit +shape, yet affect the rendering in some way. +

OpenGL - A +graphics API which exists on many different platforms.
+Gem can also be used as a wrapper for openGL, allowing to program openGL without having to +compile +

Particles - GEM objects which involve the particle +system. +

Pd +- A visual programming language for audio processing.  This is the +host application for GEM. +

Pixes - Image processing objects in GEM +

Texture mapping - Applying an image to a geometric +object. +

[return] +
  + + diff --git a/Gem/manual/Images.html b/Gem/manual/Images.html index 182d153..cc6eb99 100644 --- a/Gem/manual/Images.html +++ b/Gem/manual/Images.html @@ -1,112 +1,112 @@ - - - - - - - Images - - - -

-

-Dealing with Images

-Images are files which are loaded into GEM. The images can be manipulated, -applied to objects, and used in any number of different ways. In -this section, you will load in an image and display it on the screen. -This section will not apply the images to a geo; that occurs in -the next part of the manual. -

The pix objects are GEM objects which deal with pixels. -They do everything from loading in images to applying filters to the data. -The objects in this section of the manual only load in pix data from outside -sources. How you actually display the image is up to you. The -most common usages are with [pix_draw] and [pix_texture]. -

Warning: [pix_draw] is almost always slower than [pix_texture]. -Because [pix_draw] is easier to use than [pix_texture], it is -used in these examples. However, in any real usage or piece, [pix_texture] -should always be used instead. [pix_draw] is slow because PC -graphics accelerators do not provide hardware acceleration for that functionality. -[pix_texture] does have hardware acceleration and will be much faster. -

[pix_image] - load in an image -
[pix_multiimage] - load in multiple images -
[pix_movie] - load in a movie file -
[pix_video] - use a real time video source -

-

-[pix_image]

-[pix_image] is used to load in images. Images can be in a variety -of different formats, including TIFF, JPEG, and SGI formats. The -patch gem_pix/gemImage.pd is the simplest use of the [pix_image] object. -In this patch, the [pix_image] object loads in the file dancer.JPG. -
-

- -

As is the case with every GEM chain, this patch starts with the [gemhead] -object. The next object is [pix_image], which actually loads -the image. [pix_image] makes the file dancer.JPG the current -pixel data, which will be used in all subsequent operations in the chain. -The [translateXYZ] object is used to move the image around. -Finally, the [pix_draw] object renders the pixel data to the screen. -

The patch mentions that changing the Z in [translateXYZ] does not -change the size of the image, as would occur with a geo object like -[square]. -This is because [pix_draw] simply draws the pixel at the current raster -position, without any transformation. If you want to change the size -on the fly and rotate the image, you need to texture map the pix, which -is described in the next section. -

-

-[pix_multiimage]

-The [pix_image] object only loads in one image at time. If you -try to change the image rapidly while the patch is running, you will notice -a lag every time it has to load in a new file. To avoid this lag, -there is another object called [pix_multiimage]. If you look -at patch gem_pix/gemMultiImage.pd, you will see this object in action. -

Basically, the * in the file name is replaced by the number that you -pass in. This allows you to play sequences of images with random -access. The one downside is that every image is loaded into memory -when the object is created, so you need to have a lot of RAM to use it. -

-

[pix_movie]/[pix_film]

-These objects are used to read movie-files from disk (or if supported from the internet). - -The movie is streamed off of disk, -using whatever decompression libraries are installed on your computer. -On Windows AVI movies seem to work fine, -but there is also a prelaminary support for quicktimes (and mpeg). -On macOS-X all formats supported by the system (basically: quicktime) should work ok. -On linux the support is highly depending on what libraries are installed during compile time. -There is support for MPEG (with libmpeg1 or (preferred:) libmpeg3), -quicktime (either libquicktime or quicktime4linux; -most likely you will not be able to decode quicktimes with proprietary codecs) -and AVI (with libavifile which is able to utilize windows-dlls for (proprietary) codecs). -There is also some rudimentary support for FFMPEG. - -The right inlet of [pix_movie] -accepts a number to specify the frame to display. Look at 04.pix/04.movie.pd -for an image. -

A key fact of [pix_movie] is that it immediately sends the movie -data to OpenGL as a texture map. This means that you do not need -the [pix_texture] object in your chain. This also means that -you cannot process the movie data with pix objects. The main reason -for this is that it removes the need for a copy of all of the movie data. -If you want to apply some image-processing, you will have to use [pix_film] -(and [pix_texture] for texture-mapping). -

Some of the geos will not texture map the [pix_movie] data correctly. -Cone and sphere do not use texture coordinates when they are provided, -so when you display a movie on one of these objects, you will have a black -region (unless your movie size is a power of two...however, most movies -are 320x160 pixels or something). This will be fixed in a future -release. -

-

-pix_video

-The "image" can come from the [pix_video] object. -This means that you can use a real-time video source and display it on the screen. -

You can play with [pix_video] with the patches in 04.video/. -The patches are explained in more depth in the advanced section of the GEM manual. -

-

[return] -
- - + + + + + + + Images + + + +

+

+Dealing with Images

+Images are files which are loaded into GEM. The images can be manipulated, +applied to objects, and used in any number of different ways. In +this section, you will load in an image and display it on the screen. +This section will not apply the images to a geo; that occurs in +the next part of the manual. +

The pix objects are GEM objects which deal with pixels. +They do everything from loading in images to applying filters to the data. +The objects in this section of the manual only load in pix data from outside +sources. How you actually display the image is up to you. The +most common usages are with [pix_draw] and [pix_texture]. +

Warning: [pix_draw] is almost always slower than [pix_texture]. +Because [pix_draw] is easier to use than [pix_texture], it is +used in these examples. However, in any real usage or piece, [pix_texture] +should always be used instead. [pix_draw] is slow because PC +graphics accelerators do not provide hardware acceleration for that functionality. +[pix_texture] does have hardware acceleration and will be much faster. +

[pix_image] - load in an image +
[pix_multiimage] - load in multiple images +
[pix_movie] - load in a movie file +
[pix_video] - use a real time video source +

+

+[pix_image]

+[pix_image] is used to load in images. Images can be in a variety +of different formats, including TIFF, JPEG, and SGI formats. The +patch gem_pix/gemImage.pd is the simplest use of the [pix_image] object. +In this patch, the [pix_image] object loads in the file dancer.JPG. +
+

+ +

As is the case with every GEM chain, this patch starts with the [gemhead] +object. The next object is [pix_image], which actually loads +the image. [pix_image] makes the file dancer.JPG the current +pixel data, which will be used in all subsequent operations in the chain. +The [translateXYZ] object is used to move the image around. +Finally, the [pix_draw] object renders the pixel data to the screen. +

The patch mentions that changing the Z in [translateXYZ] does not +change the size of the image, as would occur with a geo object like +[square]. +This is because [pix_draw] simply draws the pixel at the current raster +position, without any transformation. If you want to change the size +on the fly and rotate the image, you need to texture map the pix, which +is described in the next section. +

+

+[pix_multiimage]

+The [pix_image] object only loads in one image at time. If you +try to change the image rapidly while the patch is running, you will notice +a lag every time it has to load in a new file. To avoid this lag, +there is another object called [pix_multiimage]. If you look +at patch gem_pix/gemMultiImage.pd, you will see this object in action. +

Basically, the * in the file name is replaced by the number that you +pass in. This allows you to play sequences of images with random +access. The one downside is that every image is loaded into memory +when the object is created, so you need to have a lot of RAM to use it. +

+

[pix_movie]/[pix_film]

+These objects are used to read movie-files from disk (or if supported from the internet). + +The movie is streamed off of disk, +using whatever decompression libraries are installed on your computer. +On Windows AVI movies seem to work fine, +but there is also a prelaminary support for quicktimes (and mpeg). +On macOS-X all formats supported by the system (basically: quicktime) should work ok. +On linux the support is highly depending on what libraries are installed during compile time. +There is support for MPEG (with libmpeg1 or (preferred:) libmpeg3), +quicktime (either libquicktime or quicktime4linux; +most likely you will not be able to decode quicktimes with proprietary codecs) +and AVI (with libavifile which is able to utilize windows-dlls for (proprietary) codecs). +There is also some rudimentary support for FFMPEG. + +The right inlet of [pix_movie] +accepts a number to specify the frame to display. Look at 04.pix/04.movie.pd +for an image. +

A key fact of [pix_movie] is that it immediately sends the movie +data to OpenGL as a texture map. This means that you do not need +the [pix_texture] object in your chain. This also means that +you cannot process the movie data with pix objects. The main reason +for this is that it removes the need for a copy of all of the movie data. +If you want to apply some image-processing, you will have to use [pix_film] +(and [pix_texture] for texture-mapping). +

Some of the geos will not texture map the [pix_movie] data correctly. +Cone and sphere do not use texture coordinates when they are provided, +so when you display a movie on one of these objects, you will have a black +region (unless your movie size is a power of two...however, most movies +are 320x160 pixels or something). This will be fixed in a future +release. +

+

+pix_video

+The "image" can come from the [pix_video] object. +This means that you can use a real-time video source and display it on the screen. +

You can play with [pix_video] with the patches in 04.video/. +The patches are explained in more depth in the advanced section of the GEM manual. +

+

[return] +
+ + diff --git a/Gem/manual/Input.html b/Gem/manual/Input.html index fe089d0..3b027e1 100644 --- a/Gem/manual/Input.html +++ b/Gem/manual/Input.html @@ -1,19 +1,19 @@ - - - - - - - Input devices - - - -

-

-Input devices

- -


Nothing here yet -

[return] -
  - - + + + + + + + Input devices + + + +

+

+Input devices

+ +


Nothing here yet +

[return] +
  + + diff --git a/Gem/manual/Intro.html b/Gem/manual/Intro.html index 23e8d23..165ad27 100644 --- a/Gem/manual/Intro.html +++ b/Gem/manual/Intro.html @@ -1,62 +1,62 @@ - - - - - - - GEM - Introduction - - - -

-

-Introduction

-GEM is the Graphics Environment for Multimedia. It was originally written by -Mark Danks to generate real-time computer graphics, -especially for audio-visual compositions. -Because GEM is a visual programming environment, users do not need any experience -in traditional computer languages. -

GEM is a collection of externals which allow the user to create -OpenGL -graphics within Pd, -a program for real-time audio processing by Miller -Puckette (of Max fame). -

There are many different shapes and objects, including polygonal graphics, -lighting, texture mapping, image processing, and camera motion. All of -this is possible in real-time without any previous programming experience. -Because GEM is an add-on library for Pd, -users can combine audio and graphics, controlling one medium from another. -

GEM is supported in part by a grant from the Intel -Research Council for the The Global Visual -Music project of Vibeke -Sorensen, Miller Puckette -and Rand Steiger. -

An important thing to remember is that GEM is NOT an application.  -It is a library that Pd loads at run-time.  Make sure that you see -the section on using GEM with Pd.  This -manual assumes that you have Pd working correctly and can load up patches -already.  If you do not have that working yet, look at the Pd manual -and the GEM FAQ.  Also, it is assumed that you have a basic understanding -of how to use Pd and the idea behind the data flow model.  In other -words, if I ask you to pass a message with 3 floats into an object, you -would know what I mean. -

The system requirements vary depending on your system and what you are -trying to do.  In general, you should have the most powerful computer -available and the best graphics accelerator on the market.  In reality, -people have been doing some amazing work with a Pentium II and an nVidia -Riva TNT or 3Dfx Voodoo2 card.  -If you are on an SGI, then everything from an O2 up seems to be okay.  -The biggest requirement is that you have some kind of OpenGL graphics accelerator.  -This means that a Matrox Millennium II will not run very quickly. -

The other factor is what you are trying to do.  Pushing real-time -video around requires a fast bus, which really only exists on SGIs.  -Doing thousands of texture mapped polygons is great on a PC...if it is -a constant texture.  There are many issues which mean that there is -no one answer to "Is this system good enough?".  In general, you will -have to try and see. -

GEM is now maintained by IOhannes m zmölnig. -So any bug-reports and donations should go to him instead of Mark... -

[return] -
  - - + + + + + + + GEM - Introduction + + + +

+

+Introduction

+GEM is the Graphics Environment for Multimedia. It was originally written by +Mark Danks to generate real-time computer graphics, +especially for audio-visual compositions. +Because GEM is a visual programming environment, users do not need any experience +in traditional computer languages. +

GEM is a collection of externals which allow the user to create +OpenGL +graphics within Pd, +a program for real-time audio processing by Miller +Puckette (of Max fame). +

There are many different shapes and objects, including polygonal graphics, +lighting, texture mapping, image processing, and camera motion. All of +this is possible in real-time without any previous programming experience. +Because GEM is an add-on library for Pd, +users can combine audio and graphics, controlling one medium from another. +

GEM is supported in part by a grant from the Intel +Research Council for the The Global Visual +Music project of Vibeke +Sorensen, Miller Puckette +and Rand Steiger. +

An important thing to remember is that GEM is NOT an application.  +It is a library that Pd loads at run-time.  Make sure that you see +the section on using GEM with Pd.  This +manual assumes that you have Pd working correctly and can load up patches +already.  If you do not have that working yet, look at the Pd manual +and the GEM FAQ.  Also, it is assumed that you have a basic understanding +of how to use Pd and the idea behind the data flow model.  In other +words, if I ask you to pass a message with 3 floats into an object, you +would know what I mean. +

The system requirements vary depending on your system and what you are +trying to do.  In general, you should have the most powerful computer +available and the best graphics accelerator on the market.  In reality, +people have been doing some amazing work with a Pentium II and an nVidia +Riva TNT or 3Dfx Voodoo2 card.  +If you are on an SGI, then everything from an O2 up seems to be okay.  +The biggest requirement is that you have some kind of OpenGL graphics accelerator.  +This means that a Matrox Millennium II will not run very quickly. +

The other factor is what you are trying to do.  Pushing real-time +video around requires a fast bus, which really only exists on SGIs.  +Doing thousands of texture mapped polygons is great on a PC...if it is +a constant texture.  There are many issues which mean that there is +no one answer to "Is this system good enough?".  In general, you will +have to try and see. +

GEM is now maintained by IOhannes m zmölnig. +So any bug-reports and donations should go to him instead of Mark... +

[return] +
  + + diff --git a/Gem/manual/Lighting.html b/Gem/manual/Lighting.html index dcff171..5c30fb9 100644 --- a/Gem/manual/Lighting.html +++ b/Gem/manual/Lighting.html @@ -1,107 +1,107 @@ - - - - - - - Lighting - - - -

-

-Lighting

-Lighting is an important factor is how we perceive the quality of an image. -For example, without lighting and shading, a sphere would just look like -a circle. GEM provides two types of lights, a local light and world -light. -

OpenGL uses a vertex lighting model. This means that for every -vertex in the scene, the influence of the light is calculated. The -color for the polygon is then modified by the light value of all of the -vertices. This generally produces a very smooth effect, but you will -occasionally run into rendering artifacts, especially if you use local -lights. For example, imagine you have a local light close a large -square. The corners of the square are far away from the light, so -none of them will be lit very brightly, even though the light itself is -very close to the surface of the square. -

It is important to realize that lighting is an expensive operation to -use. The number of polygons that you will be able to render will -be much lower if lighting is turned on. As usual, the complexity -of the scene and the speed of your computer and graphics card will greatly -affect your frame rate. -

GEM has only a maximum of 8 lights at one time. If you try to -create more lights than that, you will get an error message. -

Activate lighting -
[world_light] - A directional light -
[light] - A point light in the world -
Moving lights -

-

-Activate lighting

-Lighting is activated by sending a message to [gemwin]. If you -send "lighting 1", then lighting will be turned on. If you send "lighting -0", then lighting will be turned off. The lighting state is kept -even if you destroy the gemwin. This means that if you close a patch -and open another one, the lighting will still be the same. -

Individual lights can be turned on and off by sending a 1 or 0 to the -left inlet of the light object itself. -

-

-[world_light]

-A [world_light] is a light which exists infintely far away. -This reduces the computation needed, so your patch can run faster, but -it means that all of the light rays are parallel. The [world_light] -is good for objects like the sun and other lighting affects. This -means that translating a [world_light] has no effect, although rotation -does. -

The following patch is 03.lighting/01.world_light.pd. -

-

- -

The [world_light] has one extra inlet. The right inlet accepts -three floats to set the color of the light. A [color] object -would do nothing. In this case, the light is being set to purple. -The [world_light] also accepts a debug message. The debug message -turns on and off a graphical representation of the light in the scene. -The [world_light] looks like a cone. The cone shows the direction -that the light is coming from. Remember that the actual position -of the light does not matter, so geos behind the cone will still be lit. -It is the direction of the light that matters. This is why you can -rotate the light. -

-

-[light]

-A [light] object generates a point light in the world. Because -the light is local to the scene, there is more math to generate the effect -of the light on the vertices. However, unlike a [world_light], -you can translate the [light] object. -

Below is the patch 03.lighting/02.light.pd. -

-

- -

The [light] object has a right inlet for the color, just light -the [world_light] object. As this patch shows, the light can -be moved around the scene with both [rotate] and [translate] -objects. If you were to set the translate X value equal to 1.0, then -the sphere would not be lit at all. This is because the light would -be inside of the sphere. When you turn on the debug representation, -it is a sphere with its origin where the light it. The [light] -object does not have any size. It exists as a point source. -

-

-Moving lights

-The patch 03.lighting/03.controlLights.pd allows you to move a [light] -and [world_light] object in the same scene to see the difference between -the two objects. -

The patch 03.lighting/04.moveSpheres.pd is an example which moves -two spheres around the world. Turn on and off the individual lights -for a demonstration of a local versus infinite light. -

The patch 03.lighting/05.materials.pd uses the material objects to -selectively control the color of the object. Notice that the diffuse object -sets the "overall" color, while the specular objects sets the bright reflective -area where the light directly shines. -

-

[return] -
- - + + + + + + + Lighting + + + +

+

+Lighting

+Lighting is an important factor is how we perceive the quality of an image. +For example, without lighting and shading, a sphere would just look like +a circle. GEM provides two types of lights, a local light and world +light. +

OpenGL uses a vertex lighting model. This means that for every +vertex in the scene, the influence of the light is calculated. The +color for the polygon is then modified by the light value of all of the +vertices. This generally produces a very smooth effect, but you will +occasionally run into rendering artifacts, especially if you use local +lights. For example, imagine you have a local light close a large +square. The corners of the square are far away from the light, so +none of them will be lit very brightly, even though the light itself is +very close to the surface of the square. +

It is important to realize that lighting is an expensive operation to +use. The number of polygons that you will be able to render will +be much lower if lighting is turned on. As usual, the complexity +of the scene and the speed of your computer and graphics card will greatly +affect your frame rate. +

GEM has only a maximum of 8 lights at one time. If you try to +create more lights than that, you will get an error message. +

Activate lighting +
[world_light] - A directional light +
[light] - A point light in the world +
Moving lights +

+

+Activate lighting

+Lighting is activated by sending a message to [gemwin]. If you +send "lighting 1", then lighting will be turned on. If you send "lighting +0", then lighting will be turned off. The lighting state is kept +even if you destroy the gemwin. This means that if you close a patch +and open another one, the lighting will still be the same. +

Individual lights can be turned on and off by sending a 1 or 0 to the +left inlet of the light object itself. +

+

+[world_light]

+A [world_light] is a light which exists infintely far away. +This reduces the computation needed, so your patch can run faster, but +it means that all of the light rays are parallel. The [world_light] +is good for objects like the sun and other lighting affects. This +means that translating a [world_light] has no effect, although rotation +does. +

The following patch is 03.lighting/01.world_light.pd. +

+

+ +

The [world_light] has one extra inlet. The right inlet accepts +three floats to set the color of the light. A [color] object +would do nothing. In this case, the light is being set to purple. +The [world_light] also accepts a debug message. The debug message +turns on and off a graphical representation of the light in the scene. +The [world_light] looks like a cone. The cone shows the direction +that the light is coming from. Remember that the actual position +of the light does not matter, so geos behind the cone will still be lit. +It is the direction of the light that matters. This is why you can +rotate the light. +

+

+[light]

+A [light] object generates a point light in the world. Because +the light is local to the scene, there is more math to generate the effect +of the light on the vertices. However, unlike a [world_light], +you can translate the [light] object. +

Below is the patch 03.lighting/02.light.pd. +

+

+ +

The [light] object has a right inlet for the color, just light +the [world_light] object. As this patch shows, the light can +be moved around the scene with both [rotate] and [translate] +objects. If you were to set the translate X value equal to 1.0, then +the sphere would not be lit at all. This is because the light would +be inside of the sphere. When you turn on the debug representation, +it is a sphere with its origin where the light it. The [light] +object does not have any size. It exists as a point source. +

+

+Moving lights

+The patch 03.lighting/03.controlLights.pd allows you to move a [light] +and [world_light] object in the same scene to see the difference between +the two objects. +

The patch 03.lighting/04.moveSpheres.pd is an example which moves +two spheres around the world. Turn on and off the individual lights +for a demonstration of a local versus infinite light. +

The patch 03.lighting/05.materials.pd uses the material objects to +selectively control the color of the object. Notice that the diffuse object +sets the "overall" color, while the specular objects sets the bright reflective +area where the light directly shines. +

+

[return] +
+ + diff --git a/Gem/manual/ListObjects.html b/Gem/manual/ListObjects.html index 2708993..da6ab37 100644 --- a/Gem/manual/ListObjects.html +++ b/Gem/manual/ListObjects.html @@ -1,231 +1,231 @@ - - - - - - - List of GEM objects - - - -

-

-List of GEM objects

-Controls -
Manipulators -
Geos -
Particles -
Nongeos -
Pixes -
TV -
MarkEx -

-

Controls -
gemhead - the start of rendering chain -
gemwin - the window manager -
gemmouse - outputs the mouse position and buttons in the GEM window -
gemkeyboard - outputs the keycode of a key pressed when you are in the GEM window (there might be different keycodes in Windows/Linux) -
gemkeyname - outputs a symbolic description of a key pressed when you are in the GEM window (there might be different symbols in Windows/Linux) -
gemorb - outputs the position, rotation, and buttons for a Space Orb -
gemtablet - outputs the pen position, pressure, and buttons in the -GEM window -

-

-
Manipulators -
accumrotate - accumulate a rotation -
alpha - enable/disable alpha blending -
ambient - set the ambient color with a vector -
ambientRGB - set the ambient color with 3 discrete values -
camera - -
color - set the color with a vector -
colorRGB - set the color with 3 discrete values -
depth - enable/disable depth testing -
diffuse - set the diffuse color with a vector -
diffuseRGB - set the diffuse color with 3 discrete values -
emission - set the emissive color with a vector -
emissionRGB - set the emissive color with 3 discrete values -
linear_path - generate a path from an array of points -
ortho - change the view to orthogonal, with the viewport the size of -the window -
polygon_smooth - turn on anti-aliasing for the objects below -
rotate - rotate with an angle and vector -
rotateXYZ - rotate with 3 discrete values -
scale - scale with a vector -
scaleXYZ - scale with 3 discrete values -
separator - push the OpenGL state for the rest of the chain and pop -when done -
shininess - set the shininess of an object -
specular - set the specular color with a vector -
specularRGB - set the specular color with 3 discrete values -
spline_path - generate a spline from an array of knots -
translate - translate with a vector -
translateXYZ - translate with 3 discrete values - -

Geos -
circle - render a circle -
colorSquare - render a colored square (evtl. with color gradients) -
cone - render a cone -
cube - render a cube -
cuboid - render a box -
curve - render a Bezier curve -
curve3d - render a surface -
cylinder - render a cylinder -
disk - render a disk -
imageVert - make pixel colors to a height field map -
model - render an Alias|Wavefront model -
multimodel - render a series of Alias|Wavefront models, render by number -
newWave - render a wave (that is evolving over time) -
polygon - render a polygon -
primTri - a triangle primitive -
rectangle - render a rectangle -
ripple - a rectangle with distorted (over time) texture-coordinates -
rubber - a grid where you can move one of the grid-points -
slideSquare - render a number of sliding squares -
sphere - render a sphere -
square - render a square -
teapot - render a teapot -
text2d - render 2-D text (a bitmap) -
text3d - render 3-D text (polygonal) -
textextruded - render an extruded 3D-text -
textoutline - render outlined text (polygonal) -
triangle - render a triangle -

Particles -
part_head - The start of a particle group -
part_color - Set the range of colors for the new particles -
part_damp - set the damping for particles -
part_draw - Apply the actions and render the particles.  Accepts -a message "draw line" or "draw point" to change the drawing style. -
part_follow - Particles will follow each other like a snake -
part_gravity - Have the particles accelerate in a direction -
part_info - get the information (position, color, size,...) of each particle -
part_killold - Remove particles past a certain age -
part_killslow - Remove particles below a certain speed -
part_orbitpoint - Orbit the particles around a specified point -
part_render - render the remaining gem-tree as particles. -
part_size - Set the size of new particles -
part_source - Generate particles -
part_targetcolor - Change color of the particles toward the specified -color -
part_targetsize - Change size of the particles toward the specified -size -
part_velocity - Set the velocity domain -(distribution like CONE and the appropriate arguments) -
part_vertex - emit a single particle - -

Nongeos -
light - make a point light -
world_light - make a light at infinity -

Pixes -
pix_2grey - convert rgb pixels to grey (still an RGBA image) -
pix_a_2grey - convert rgb pixels to grey based on alpha channel -
pix_add - add two pixes together -
pix_aging - super8-like aging effect -
pix_alpha - set the alpha value of a pix -
pix_background - let through only pixels that differ from a static "background" image -
pix_backlight - a backlight photo effect -
pix_biquad - 2p2z-filter for subsequent images -
pix_bitmask - apply a bitmask to a pix -
pix_blob - get center of gravity -
pix_buf - buffer a pix -
pix_buffer - storage room for pixes (like [table] for floats) -
pix_buffer_read/pix_buffer_write - put/get pixes into/from a pix_buffer -
pix_chroma_key - color keying (like "blue-box") -
pix_coloralpha - set the alpha-channel of a pix as a mean-value of the color-components -
pix_colormatrix - recombine the RGBA-channels with matrix-operation -
pix_color - set the color of a pix (leaving alpha alone) -
pix_colorreduce - reduce the number of colors (statistically) -
pix_composite - composite two pixes together -
pix_convolve - convolve a pix with a kernal -
pix_coordinate - set the texture coordinates -
pix_crop - get a sub-image of a pix -
pix_curve - apply color-curves onto a pix -
pix_data - get pixel data information -
pix_delay - frame-wise delay -
pix_diff - get absolute difference of two pixes -
pix_dot - rasterize a pix with big dots -
pix_draw - draw a pix -
pix_dump - dump the pixel-data as a long list of floats -
pix_duotone - reduce the number of colors by thresholding -
pix_film - use a movie file as a pix source for image-processing -
pix_flip - flip the pixels of a pix -
pix_gain - apply a gain to a pix -
pix_grey - convert any pix into greyscale colorspace -
pix_halftone - rasterize a pix like it was printed in a newspaper -
pix_histo - get the histogram of a pix -
pix_hsv2rgb - transform a pix from HSV-colorspace into RGB-colorspace -
pix_image - load in an image file -
pix_imageInPlace - load a series of image files directly into texture-buffer, display by number -
pix_info - get information about the pix (like dimension, colorspace,...) -
pix_invert - invert a pix -
pix_kaleidoscope - as if you were looking at the pix through a kaleidoscope -
pix_levels - level adjustment -
pix_lumaoffset - y-offset pixels depending on their luminance -
pix_mask - mask a pix based on another pix -
pix_metaimage - recompose an image out of smaller versions of itself -
pix_mix - mix to pixes together -
pix_motionblur - motionblur an image -
pix_movie - use a movie file as a pix source and load it immediately into the texture-buffer -
pix_movement - set the alpha-channel with respect to the change between two frames -
pix_multiply - multiply two pixes -
pix_multiimage - load in a series of image files, display by number -
pix_normalize - normalize a pix -
pix_offset - add an offset to a pix (wrapping instead of clipping) -
pix_pix2sig~ - interpret a pix as 4 (RGBA) audio-signals -
pix_posterize - posterization photo effect -
pix_puzzle - shuffle an image -
pix_rds - generate a Random Dot Stereogram out of the image (aka: Magic Eye (tm)) -
pix_rectangle - generate a rectangle in a pix buffer -
pix_refraction - break up an image into coloured "glass-bricks" -
pix_resize - resize a pix to next power of 2 -
pix_rgb2hsv - transform a pix from RGB-colorspace into HSV-colorspace -
pix_rgba - transform a pix of any format into RGBA -
pix_roll - (sc)roll through an image (wrapping) -
pix_rtx - swap time-axis and x-axis -
pix_scanline - take every nth line of the original image -
pix_set - set the pixel-data with a long list of floats -
pix_sig2pix~ - interpret 4 audio-signals as (RGBA) image-data -
pix_snap - capture the render window into a pix -
pix_snap2tex - capture the render window directly as a texture -
pix_subtract - subtract two pixes -
pix_tIIR - time-base Infinite-Impulse-Response filter (for motion-bluring,...) with settable number of poles/zeros -
pix_takealpha - take the alpha channel of one pix and put it into another pix -
pix_texture - use a pix as a texture map -
pix_threshold - apply a threshold to a pix -
pix_video - use a video camera as a pix source -
pix_write - capture the render window to disk -
pix_zoom - zoom into a pix (using OpenGL) - -

openGL -there are more than 250 objects that -form a complete wrapper around the openGL set of functions -(as defined in the openGL-1.2 standard).
-each openGL-function is prefixed with "GEM", eg: -[GEMglVertex3f] is wrapped around glVertex3f. - -

MarkEx -
alternate - alternate between two outlets -
average - average a sequence of numbers -
change - only output on change -
counter - count bangs -
invert - non-zero numbers to zero, zero to 1 -
multiselect/multisel - a select object which accepts a list in the -right inlet -
oneshot - send a bang, then block until reset -
randomF / randF - floating point random numbers -
strcat - string concatentation -
tripleLine - do a line with three numbers -
tripleRand - random with three numbers -
vector+ / v+ - add a scalar to a vector -
vector- / v- - subtract a scalar from a vector -
vector* / v* - multiply a vector by a scalar -
vector/ / v/ - divide a vector by a scalar -
vectorpack / vpack - attach a scalar to the end of a vector -
rgb2hsv - convert a list of three floats from RGB to an HSV value -
hsv2rgb - convert a list of three floats from HSV to an RGB value -
abs~ - absolute value of a signal -
reson~ - resonant filter -

[return] -
  -
  - - + + + + + + + List of GEM objects + + + +

+

+List of GEM objects

+Controls +
Manipulators +
Geos +
Particles +
Nongeos +
Pixes +
TV +
MarkEx +

+

Controls +
gemhead - the start of rendering chain +
gemwin - the window manager +
gemmouse - outputs the mouse position and buttons in the GEM window +
gemkeyboard - outputs the keycode of a key pressed when you are in the GEM window (there might be different keycodes in Windows/Linux) +
gemkeyname - outputs a symbolic description of a key pressed when you are in the GEM window (there might be different symbols in Windows/Linux) +
gemorb - outputs the position, rotation, and buttons for a Space Orb +
gemtablet - outputs the pen position, pressure, and buttons in the +GEM window +

+

+
Manipulators +
accumrotate - accumulate a rotation +
alpha - enable/disable alpha blending +
ambient - set the ambient color with a vector +
ambientRGB - set the ambient color with 3 discrete values +
camera - +
color - set the color with a vector +
colorRGB - set the color with 3 discrete values +
depth - enable/disable depth testing +
diffuse - set the diffuse color with a vector +
diffuseRGB - set the diffuse color with 3 discrete values +
emission - set the emissive color with a vector +
emissionRGB - set the emissive color with 3 discrete values +
linear_path - generate a path from an array of points +
ortho - change the view to orthogonal, with the viewport the size of +the window +
polygon_smooth - turn on anti-aliasing for the objects below +
rotate - rotate with an angle and vector +
rotateXYZ - rotate with 3 discrete values +
scale - scale with a vector +
scaleXYZ - scale with 3 discrete values +
separator - push the OpenGL state for the rest of the chain and pop +when done +
shininess - set the shininess of an object +
specular - set the specular color with a vector +
specularRGB - set the specular color with 3 discrete values +
spline_path - generate a spline from an array of knots +
translate - translate with a vector +
translateXYZ - translate with 3 discrete values + +

Geos +
circle - render a circle +
colorSquare - render a colored square (evtl. with color gradients) +
cone - render a cone +
cube - render a cube +
cuboid - render a box +
curve - render a Bezier curve +
curve3d - render a surface +
cylinder - render a cylinder +
disk - render a disk +
imageVert - make pixel colors to a height field map +
model - render an Alias|Wavefront model +
multimodel - render a series of Alias|Wavefront models, render by number +
newWave - render a wave (that is evolving over time) +
polygon - render a polygon +
primTri - a triangle primitive +
rectangle - render a rectangle +
ripple - a rectangle with distorted (over time) texture-coordinates +
rubber - a grid where you can move one of the grid-points +
slideSquare - render a number of sliding squares +
sphere - render a sphere +
square - render a square +
teapot - render a teapot +
text2d - render 2-D text (a bitmap) +
text3d - render 3-D text (polygonal) +
textextruded - render an extruded 3D-text +
textoutline - render outlined text (polygonal) +
triangle - render a triangle +

Particles +
part_head - The start of a particle group +
part_color - Set the range of colors for the new particles +
part_damp - set the damping for particles +
part_draw - Apply the actions and render the particles.  Accepts +a message "draw line" or "draw point" to change the drawing style. +
part_follow - Particles will follow each other like a snake +
part_gravity - Have the particles accelerate in a direction +
part_info - get the information (position, color, size,...) of each particle +
part_killold - Remove particles past a certain age +
part_killslow - Remove particles below a certain speed +
part_orbitpoint - Orbit the particles around a specified point +
part_render - render the remaining gem-tree as particles. +
part_size - Set the size of new particles +
part_source - Generate particles +
part_targetcolor - Change color of the particles toward the specified +color +
part_targetsize - Change size of the particles toward the specified +size +
part_velocity - Set the velocity domain +(distribution like CONE and the appropriate arguments) +
part_vertex - emit a single particle + +

Nongeos +
light - make a point light +
world_light - make a light at infinity +

Pixes +
pix_2grey - convert rgb pixels to grey (still an RGBA image) +
pix_a_2grey - convert rgb pixels to grey based on alpha channel +
pix_add - add two pixes together +
pix_aging - super8-like aging effect +
pix_alpha - set the alpha value of a pix +
pix_background - let through only pixels that differ from a static "background" image +
pix_backlight - a backlight photo effect +
pix_biquad - 2p2z-filter for subsequent images +
pix_bitmask - apply a bitmask to a pix +
pix_blob - get center of gravity +
pix_buf - buffer a pix +
pix_buffer - storage room for pixes (like [table] for floats) +
pix_buffer_read/pix_buffer_write - put/get pixes into/from a pix_buffer +
pix_chroma_key - color keying (like "blue-box") +
pix_coloralpha - set the alpha-channel of a pix as a mean-value of the color-components +
pix_colormatrix - recombine the RGBA-channels with matrix-operation +
pix_color - set the color of a pix (leaving alpha alone) +
pix_colorreduce - reduce the number of colors (statistically) +
pix_composite - composite two pixes together +
pix_convolve - convolve a pix with a kernal +
pix_coordinate - set the texture coordinates +
pix_crop - get a sub-image of a pix +
pix_curve - apply color-curves onto a pix +
pix_data - get pixel data information +
pix_delay - frame-wise delay +
pix_diff - get absolute difference of two pixes +
pix_dot - rasterize a pix with big dots +
pix_draw - draw a pix +
pix_dump - dump the pixel-data as a long list of floats +
pix_duotone - reduce the number of colors by thresholding +
pix_film - use a movie file as a pix source for image-processing +
pix_flip - flip the pixels of a pix +
pix_gain - apply a gain to a pix +
pix_grey - convert any pix into greyscale colorspace +
pix_halftone - rasterize a pix like it was printed in a newspaper +
pix_histo - get the histogram of a pix +
pix_hsv2rgb - transform a pix from HSV-colorspace into RGB-colorspace +
pix_image - load in an image file +
pix_imageInPlace - load a series of image files directly into texture-buffer, display by number +
pix_info - get information about the pix (like dimension, colorspace,...) +
pix_invert - invert a pix +
pix_kaleidoscope - as if you were looking at the pix through a kaleidoscope +
pix_levels - level adjustment +
pix_lumaoffset - y-offset pixels depending on their luminance +
pix_mask - mask a pix based on another pix +
pix_metaimage - recompose an image out of smaller versions of itself +
pix_mix - mix to pixes together +
pix_motionblur - motionblur an image +
pix_movie - use a movie file as a pix source and load it immediately into the texture-buffer +
pix_movement - set the alpha-channel with respect to the change between two frames +
pix_multiply - multiply two pixes +
pix_multiimage - load in a series of image files, display by number +
pix_normalize - normalize a pix +
pix_offset - add an offset to a pix (wrapping instead of clipping) +
pix_pix2sig~ - interpret a pix as 4 (RGBA) audio-signals +
pix_posterize - posterization photo effect +
pix_puzzle - shuffle an image +
pix_rds - generate a Random Dot Stereogram out of the image (aka: Magic Eye (tm)) +
pix_rectangle - generate a rectangle in a pix buffer +
pix_refraction - break up an image into coloured "glass-bricks" +
pix_resize - resize a pix to next power of 2 +
pix_rgb2hsv - transform a pix from RGB-colorspace into HSV-colorspace +
pix_rgba - transform a pix of any format into RGBA +
pix_roll - (sc)roll through an image (wrapping) +
pix_rtx - swap time-axis and x-axis +
pix_scanline - take every nth line of the original image +
pix_set - set the pixel-data with a long list of floats +
pix_sig2pix~ - interpret 4 audio-signals as (RGBA) image-data +
pix_snap - capture the render window into a pix +
pix_snap2tex - capture the render window directly as a texture +
pix_subtract - subtract two pixes +
pix_tIIR - time-base Infinite-Impulse-Response filter (for motion-bluring,...) with settable number of poles/zeros +
pix_takealpha - take the alpha channel of one pix and put it into another pix +
pix_texture - use a pix as a texture map +
pix_threshold - apply a threshold to a pix +
pix_video - use a video camera as a pix source +
pix_write - capture the render window to disk +
pix_zoom - zoom into a pix (using OpenGL) + +

openGL +there are more than 250 objects that +form a complete wrapper around the openGL set of functions +(as defined in the openGL-1.2 standard).
+each openGL-function is prefixed with "GEM", eg: +[GEMglVertex3f] is wrapped around glVertex3f. + +

MarkEx +
alternate - alternate between two outlets +
average - average a sequence of numbers +
change - only output on change +
counter - count bangs +
invert - non-zero numbers to zero, zero to 1 +
multiselect/multisel - a select object which accepts a list in the +right inlet +
oneshot - send a bang, then block until reset +
randomF / randF - floating point random numbers +
strcat - string concatentation +
tripleLine - do a line with three numbers +
tripleRand - random with three numbers +
vector+ / v+ - add a scalar to a vector +
vector- / v- - subtract a scalar from a vector +
vector* / v* - multiply a vector by a scalar +
vector/ / v/ - divide a vector by a scalar +
vectorpack / vpack - attach a scalar to the end of a vector +
rgb2hsv - convert a list of three floats from RGB to an HSV value +
hsv2rgb - convert a list of three floats from HSV to an RGB value +
abs~ - absolute value of a signal +
reson~ - resonant filter +

[return] +
  +
  + + diff --git a/Gem/manual/Particles.html b/Gem/manual/Particles.html index 7b8ceb6..4a4f80c 100644 --- a/Gem/manual/Particles.html +++ b/Gem/manual/Particles.html @@ -1,19 +1,19 @@ - - - - - - - Particles - - - -

-

-Particles

- -


Nothing here yet -

[return] -
  - - + + + + + + + Particles + + + +

+

+Particles

+ +


Nothing here yet +

[return] +
  + + diff --git a/Gem/manual/Pixes.html b/Gem/manual/Pixes.html index badf8bc..6b90842 100644 --- a/Gem/manual/Pixes.html +++ b/Gem/manual/Pixes.html @@ -1,105 +1,105 @@ - - - - - - - Pixes (image processing) - - - -

-

-Image processing

-The pix objects are used to do image processing to pixel data. If -you load in an image with [pix_image], then you can change what the -image looks like before rendering it out -

In general, processing images is extremely expensive, so you -probably cannot have that many active pix objects. GEM only reprocesses -images when the source image changes or one of the parameters for a pix -object changes. This means that GEM will only process an image when -something is different, instead of every frame. If you want to do -a lot of processing at start up, but then not change anything once the -patch is running, GEM will only do the computation once.
-Modern CPUs use SIMD (Single Instruction - Multiple Data) (like MMX, SSE2, altivec) -to make pixel-processing more effective (by processing data parallely). -Until now, only the macOS version of Gem has support for SIMD for some pix-objects. -MMX/SSE2 boosts will hopefully come in future Gem-releases. - -

The pix objects are divided into two general groups, those which take -one input, and those which require two input images. For example, -[pix_invert] -will "invert" all of the pixels (if a pixel is white, it will change to -black), while [pix_add] will add two images together. -

Only some of the pix objects are described here. Look in the reference -patches for explanations for the other pix objects. -

[pix_invert] - invert the pixel data -
[pix_add] - add two pixes together -
[pix_mask] - create an alpha mask -
[pix_convolve] - convolve a pix with a kernel -

-

-[pix_invert]

-[pix_invert] inverts the pixels in an image. To use [pix_invert], -simply make sure that you have already loaded an image into the chain. -In the following patch, the fractal image will be inverted. -
-

- -

Here is the difference between the fractal image and the inverted version. -

-

- -

-

-pix_add

-[pix_add] does what you would expect. It adds two images together. -
-

- -

This patch adds the fractal image with a car image. The processed -image will often contain a lot of white pixels, because the data is just -added together. This occurs in the resulting image, shown below. -

-

- -


-

-

-pix_mask

-[pix_mask] is used to create an alpha mask from another image. -In the following example (gem_pix/gemMaskDancer.pd), the fractal image's -alpha channel is replaced by the dancer image. If the [alpha] -object was removed, then you would just see the solid fractal image (because -the alpha channel wouldn't be used). -

In other words, images are composed of a red, a green, a blue, and an -alpha channel. The alpha channel is the transparency of the pixel. - -[pix_mask] only modifies the alpha channel and does not touch the -red, green, or blue data. -

-

- -

The result is this image. -

-

- -

-

-pix_convolve

-[pix_convolve] convolves pix data with a convolution kernel. -Basically, you can get really nice effects if you choose the correct kernel...and -garbage if you choose the wrong one. -

Edge detection is done with a convolution kernel, as is smoothing. -The biggest problem is that convolving an image is about the most expensive -operation that you can do in GEM. -

Look at gem_pix/gemPixConvolve.pd to get an idea of some of the kernels -that you can send to [pix_convolve] and the effects that you can get. -

If you want to learn the math behind convolution, then find any standard -image processing (or audio processing book, this is just 2D convolution). -
-

-

[return] -
- - + + + + + + + Pixes (image processing) + + + +

+

+Image processing

+The pix objects are used to do image processing to pixel data. If +you load in an image with [pix_image], then you can change what the +image looks like before rendering it out +

In general, processing images is extremely expensive, so you +probably cannot have that many active pix objects. GEM only reprocesses +images when the source image changes or one of the parameters for a pix +object changes. This means that GEM will only process an image when +something is different, instead of every frame. If you want to do +a lot of processing at start up, but then not change anything once the +patch is running, GEM will only do the computation once.
+Modern CPUs use SIMD (Single Instruction - Multiple Data) (like MMX, SSE2, altivec) +to make pixel-processing more effective (by processing data parallely). +Until now, only the macOS version of Gem has support for SIMD for some pix-objects. +MMX/SSE2 boosts will hopefully come in future Gem-releases. + +

The pix objects are divided into two general groups, those which take +one input, and those which require two input images. For example, +[pix_invert] +will "invert" all of the pixels (if a pixel is white, it will change to +black), while [pix_add] will add two images together. +

Only some of the pix objects are described here. Look in the reference +patches for explanations for the other pix objects. +

[pix_invert] - invert the pixel data +
[pix_add] - add two pixes together +
[pix_mask] - create an alpha mask +
[pix_convolve] - convolve a pix with a kernel +

+

+[pix_invert]

+[pix_invert] inverts the pixels in an image. To use [pix_invert], +simply make sure that you have already loaded an image into the chain. +In the following patch, the fractal image will be inverted. +
+

+ +

Here is the difference between the fractal image and the inverted version. +

+

+ +

+

+pix_add

+[pix_add] does what you would expect. It adds two images together. +
+

+ +

This patch adds the fractal image with a car image. The processed +image will often contain a lot of white pixels, because the data is just +added together. This occurs in the resulting image, shown below. +

+

+ +


+

+

+pix_mask

+[pix_mask] is used to create an alpha mask from another image. +In the following example (gem_pix/gemMaskDancer.pd), the fractal image's +alpha channel is replaced by the dancer image. If the [alpha] +object was removed, then you would just see the solid fractal image (because +the alpha channel wouldn't be used). +

In other words, images are composed of a red, a green, a blue, and an +alpha channel. The alpha channel is the transparency of the pixel. + +[pix_mask] only modifies the alpha channel and does not touch the +red, green, or blue data. +

+

+ +

The result is this image. +

+

+ +

+

+pix_convolve

+[pix_convolve] convolves pix data with a convolution kernel. +Basically, you can get really nice effects if you choose the correct kernel...and +garbage if you choose the wrong one. +

Edge detection is done with a convolution kernel, as is smoothing. +The biggest problem is that convolving an image is about the most expensive +operation that you can do in GEM. +

Look at gem_pix/gemPixConvolve.pd to get an idea of some of the kernels +that you can send to [pix_convolve] and the effects that you can get. +

If you want to learn the math behind convolution, then find any standard +image processing (or audio processing book, this is just 2D convolution). +
+

+

[return] +
+ + diff --git a/Gem/manual/Texture.html b/Gem/manual/Texture.html index 1de889c..0e35a1d 100644 --- a/Gem/manual/Texture.html +++ b/Gem/manual/Texture.html @@ -1,126 +1,126 @@ - - - - - - - Texture mapping - - - -

-

-Texture Mapping

-Texture mapping is the act of applying -pixel data to a geometric object. In GEM, this is achieved with the -[pix_texture] -object. It is important to understand that the -[pix_texture] -object merely sets the pix as the current texture. It does not do -any rendering! You need to use a geo object which does texture mapping. -All of the basic geo objects can texture map, such as [square] or -[sphere]. -

-

A simple example of texture mapping is the following patch: -

-

- -

This patch can be found at 07.texture/01.texture.pd. Change -the number box connected to the rotate object to see what a texture map -on a cube looks like. -

The [pix_image] object loads in the fractal image file. The -[pix_texture] -object says that the pix data should be used as a texture map. Notice -that this is different than the previous manual section when we used the -[pix_draw] object. The final object in the chain is the [cube] -object. Because we have enabled texture mapping with the [pix_texture] -object, the cube takes the pix data and applies it to the geometry. -

-

Texture mapping can be used with any GEM object. In the previous -manual section, you saw how to load in pix data with a variety of objects, -including [pix_multiimage] and [pix_video]. All of these -objects can be used with the [pix_texture] object. -

Because the pix data is applied to geometry, you can move, rotate, and -scale the image. This is extremely useful on the [square] object. -Instead of doing a one-to-one pixel mapping as occurs with the [pix_draw] -object, you can resize and reshape the image. -

OpenGL originally required that images must have dimensions that are power-of-2, such as 64, 128, or 256. This restriction has been released with recent gfx-cards -(like some radeon/nvidia products). -However, if the width or height of an image is not a power of two, -then the [pix_texture] object will take care of this, -and still render it (depending on you hardware with some tricks). -You can thus texture images of any size, but since this is based on tricking -the texture-coordinates, [pix_coordinate] might not give the wanted result any more. -

-

The example patch 07.texture/02.moveImages.pd is a much more complex -patch which uses alpha blending to create a transparent object, in this -case, the dancer. Make sure to turn on the rotation with the [metro] -object. -

-

People have been asking how textures are handled in GEM. Here -is a long explanation from an email which I wrote. -

Here is how textures are dealt with under OpenGL and hardware -accelerators. This can obviously change in the future, but right -now, I am fairly certain that the info is correct (I make games in my day -job, so I have vested interest in this :-) -

The amount of memory (VRAM) on the card (12mb for Voodoo2, -16mb for TNT, 64mb for GeForce2, etc) is used for both textures (TRAM) -and frame buffer space. If you have a large rendering window, like -1600x1200, it will take up 1600x1200x4x3 in 32-bit mode with double buffering -and a Z buffer (or 23mb). Most people run at TV resolution, like -NTSC, so it takes 640x480x4x3 = 3.7mb All of the space left -is for textures onboard the card (FYI, if you have heard that people are -having problems with the PlayStation2, notice that it only has 4mb of VRAM...not -much onboard texture space, huh? :-) Thankfully it has an extremely -fast DMA bus) -

Sooo, when GEM "creates" a texture, it immediately tries -to send the texture to the card, which uses some of the left over space -in the VRAM. If you had a 640x480 window on a Voodoo2, you have ~8mb -of texture space left over. On a GeForce2, ~60mb. The problem -is what happens if you want more textures than can fit into TRAM. -OpenGL requires that the video drivers deal with the problem, so GEM doesn't -care too much (more about this later). -

In most cases, the drivers cache the textures in main memory -and if a texture is requested for rendering and it isn't resident on the -card, it will download it. If you have AGP, then this is pretty quick, -although none of 3dfx cards really take advantage of this (ie, those cards -are about the same speed as the PCI bus). So depending on the number -of textures, and how complex the scene is, you might be able to display -more textures than you have TRAM. -

One slowdown that can happen with GEM is that it makes a -copy of the image before sending it down the chain of objects. If -you are constantly changing images with a pix_multiimage, this can be a -performance hit, but you can modify the actual pixel data with the pix -objects. The pixels aren't sent to the graphics card until the pix_texture -object is reached. -

GEM tries to help with this with a few objects. pix_imageInPlace -acts much the same as pix_multiimage, but it downloads _every_ image in -the sequence to the card when a download message is recieved. It -also immediately turns on texturing, instead of making a copy (ie, you -don't need a pix_texture object). Much faster, but not as flexible. -pix_movie does much the same thing. It sends the pixel data without -copying it if there is a new frame to display. -

The entire pix system uses a caching system so that the copying -and processing only occurs if something actually changes. For example, -if you had a pix_threshold object, it would only process when rendering -started...and every time that the values actually changed. You can -use pix_buf to isolate parts which don't change from those that do, but -it involves another copy. -

On the Voodoo2, the hardware itself limits textures to 256x256...this -will never change. The newest Voodoo5 boards have a higher texture -size. -

If you load the _exact_ same image (this means the exact -same file/path name), then the pix_image has a cache system which means -that it is only loaded into the -
computers memory once. However, each pix_image still sends -its own copy down to the gfx card. -

You could use a single [pix_image]/[pix_texture] with [separator] -to do this...I have done it a lot in the past. -

The reason that [pix_image] doesn't share the actual texture -data is that you can modify the pixel data with other pix objects...[pix_image] -doesn't actually send the texture data to the gfx card, [pix_texture] does. -

-

[return] -
- - + + + + + + + Texture mapping + + + +

+

+Texture Mapping

+Texture mapping is the act of applying +pixel data to a geometric object. In GEM, this is achieved with the +[pix_texture] +object. It is important to understand that the +[pix_texture] +object merely sets the pix as the current texture. It does not do +any rendering! You need to use a geo object which does texture mapping. +All of the basic geo objects can texture map, such as [square] or +[sphere]. +

+

A simple example of texture mapping is the following patch: +

+

+ +

This patch can be found at 07.texture/01.texture.pd. Change +the number box connected to the rotate object to see what a texture map +on a cube looks like. +

The [pix_image] object loads in the fractal image file. The +[pix_texture] +object says that the pix data should be used as a texture map. Notice +that this is different than the previous manual section when we used the +[pix_draw] object. The final object in the chain is the [cube] +object. Because we have enabled texture mapping with the [pix_texture] +object, the cube takes the pix data and applies it to the geometry. +

+

Texture mapping can be used with any GEM object. In the previous +manual section, you saw how to load in pix data with a variety of objects, +including [pix_multiimage] and [pix_video]. All of these +objects can be used with the [pix_texture] object. +

Because the pix data is applied to geometry, you can move, rotate, and +scale the image. This is extremely useful on the [square] object. +Instead of doing a one-to-one pixel mapping as occurs with the [pix_draw] +object, you can resize and reshape the image. +

OpenGL originally required that images must have dimensions that are power-of-2, such as 64, 128, or 256. This restriction has been released with recent gfx-cards +(like some radeon/nvidia products). +However, if the width or height of an image is not a power of two, +then the [pix_texture] object will take care of this, +and still render it (depending on you hardware with some tricks). +You can thus texture images of any size, but since this is based on tricking +the texture-coordinates, [pix_coordinate] might not give the wanted result any more. +

+

The example patch 07.texture/02.moveImages.pd is a much more complex +patch which uses alpha blending to create a transparent object, in this +case, the dancer. Make sure to turn on the rotation with the [metro] +object. +

+

People have been asking how textures are handled in GEM. Here +is a long explanation from an email which I wrote. +

Here is how textures are dealt with under OpenGL and hardware +accelerators. This can obviously change in the future, but right +now, I am fairly certain that the info is correct (I make games in my day +job, so I have vested interest in this :-) +

The amount of memory (VRAM) on the card (12mb for Voodoo2, +16mb for TNT, 64mb for GeForce2, etc) is used for both textures (TRAM) +and frame buffer space. If you have a large rendering window, like +1600x1200, it will take up 1600x1200x4x3 in 32-bit mode with double buffering +and a Z buffer (or 23mb). Most people run at TV resolution, like +NTSC, so it takes 640x480x4x3 = 3.7mb All of the space left +is for textures onboard the card (FYI, if you have heard that people are +having problems with the PlayStation2, notice that it only has 4mb of VRAM...not +much onboard texture space, huh? :-) Thankfully it has an extremely +fast DMA bus) +

Sooo, when GEM "creates" a texture, it immediately tries +to send the texture to the card, which uses some of the left over space +in the VRAM. If you had a 640x480 window on a Voodoo2, you have ~8mb +of texture space left over. On a GeForce2, ~60mb. The problem +is what happens if you want more textures than can fit into TRAM. +OpenGL requires that the video drivers deal with the problem, so GEM doesn't +care too much (more about this later). +

In most cases, the drivers cache the textures in main memory +and if a texture is requested for rendering and it isn't resident on the +card, it will download it. If you have AGP, then this is pretty quick, +although none of 3dfx cards really take advantage of this (ie, those cards +are about the same speed as the PCI bus). So depending on the number +of textures, and how complex the scene is, you might be able to display +more textures than you have TRAM. +

One slowdown that can happen with GEM is that it makes a +copy of the image before sending it down the chain of objects. If +you are constantly changing images with a pix_multiimage, this can be a +performance hit, but you can modify the actual pixel data with the pix +objects. The pixels aren't sent to the graphics card until the pix_texture +object is reached. +

GEM tries to help with this with a few objects. pix_imageInPlace +acts much the same as pix_multiimage, but it downloads _every_ image in +the sequence to the card when a download message is recieved. It +also immediately turns on texturing, instead of making a copy (ie, you +don't need a pix_texture object). Much faster, but not as flexible. +pix_movie does much the same thing. It sends the pixel data without +copying it if there is a new frame to display. +

The entire pix system uses a caching system so that the copying +and processing only occurs if something actually changes. For example, +if you had a pix_threshold object, it would only process when rendering +started...and every time that the values actually changed. You can +use pix_buf to isolate parts which don't change from those that do, but +it involves another copy. +

On the Voodoo2, the hardware itself limits textures to 256x256...this +will never change. The newest Voodoo5 boards have a higher texture +size. +

If you load the _exact_ same image (this means the exact +same file/path name), then the pix_image has a cache system which means +that it is only loaded into the +
computers memory once. However, each pix_image still sends +its own copy down to the gfx card. +

You could use a single [pix_image]/[pix_texture] with [separator] +to do this...I have done it a lot in the past. +

The reason that [pix_image] doesn't share the actual texture +data is that you can modify the pixel data with other pix objects...[pix_image] +doesn't actually send the texture data to the gfx card, [pix_texture] does. +

+

[return] +
+ + diff --git a/Gem/manual/Utility.html b/Gem/manual/Utility.html index c8f6e17..b2e619e 100644 --- a/Gem/manual/Utility.html +++ b/Gem/manual/Utility.html @@ -1,149 +1,149 @@ - - - - - - - Utility objects - - - -

-

-Utility objects

-There are a number of objects which were written to make it easier to use -both GEM and pd.  For instance, you often pass around 3 floats at -a time in GEM, either for position or colors.  To help with this, -there are a collection of vector objects.  Use the list below to find -out about the objects. -

These objects used to be in a separate library called MarkEx, but they -have now been folded into GEM. -

counter - count the number of bangs -
average - average a series of numbers together -
change - only output when there is a change in -the number -
invert - invert a number -
randomF/randF - floating point random number -
tripleLine - line object for 3 values -
tripleRand - three random numbers -
vector objects - process a series of numbers -
hsv2rgb and rgb2hsv - convert between RGB and -HSV color space -

-

-counter

- -
- -

The inlets are: -
bang (increment or decrement the counter) -
set direction (1 = count up, 2 = count down, 3 = count up and down) -
set low value -
set hight value -
The outlet is the current count. -

So in this case, the top counter will count up from 1 to 10.  -The bottom counter will count up from 2 to 5. -

The counter also accepts the messages reset and clear.  -Reset immediately sets the counter to its low value and outputs the value.  -The clear message means that the next bang will set the counter -to its low value. -

-

-average

-The average object just averages a series of numbers as they come -in.  The left inlet accepts a single float.  It then outputs -the current average.  The default number of floats to average together -is 10, but that can be changed by sending a new value to the right inlet. -

The average object also accepts the messages clear and reset.  -Clear will immediately set all of the values that the object has been storing -for averaging to 0.  With the reset message, you must pass in a number -to set all of the values. -

-

-change

-Change only accepts a number into its left inlet.  If the number -is the same as the last number sent to the change object, then it -does nothing.  If the number is different, then the change -object will output the new number and store it for the next comparision. -

This object is very useful for the == object and others like it, since -they send a 0 or a 1 every time they do a comparision, and you usually -only care when the state actually changes. -

-

-invert

-The invert object is very simple.  If the number sent to its -left inlet is equal to 0., then invert outputs a 1.  If the -number is not equal to 0., the invert outputs a 0. -

-

-randomF/randF

-One problem with the random object in pd is that it only sends out -integers.  This a real problem in GEM, where you often want a value -between 0 and 1.  randomF is exactly like the random -object. -

When the left inlet gets a bang, randomF outputs a random number -between 0 and the given range.  The range can be set with a number -to the right inlet. -

randF is just an alternate name for randomF. -

-

-tripleLine

- -
- -

The line object is really great for dealing with a single number.  -To do a line with 3 values, like an RGB color value, means that you have -to unpack, do a line, then repack the number.  Not only is -it a pain, but it expensive computationally. -

tripleLine behaves just like the line object, only it -accepts three numbers to interpolate between.  In the example, tripleLine -will interpolate from the current values to 1., .2, .4 over 1000 milliseconds.  -The default output resolution is 50 milliseconds, which is the same default -rendering time.  Going faster with GEM objects will not produce any -benefit, unless you increase the frames per second. -

-

-tripleRand

- -
- -

Just as using tripleLine makes it easier to interpolate between -3 values at once, tripleRand makes it easy to generate three random -values.  In the above example, when the bang is sent, tripleRand -will create three values and output them, with the first between 0 - 1, -the second between 0 - .5, and the third from 0 - .8. -

-

-Vector objects

-The vector math objects are -
vector+ or v+ -
vector- or v- -
vector* or v* -
vector/ or v/ -
All of the above objects perform math on a list of numbers.  The -left inlet accepts a list of numbers of any length.  The right inlet -accepts a single value, which is the operand for the computation.  -In other words, they work just like the normal *, +, -, and / objects, -except they can handle more than one number in the left inlet. -

There are two other objects which are also useful. -

The first is vectorabs or vabs. It computes the absolute -value on a list of numbers. -

The second object is vectorpack or vpack. vpack -accepts a list of numbers in the left inlet and a single number into the -right inlet.  The output is a single list of numbers that is the vector -with the single number appended to the end.  This is very useful when -you want to change the time for a tripleLine without unpacking and -repacking all of the data. -

-

-hsv2rgb and rgb2hsv

-These two objects convert three numbers between HSV and RGB color space.  -HSV stands for hue, saturation, and value.  The simple way to think -of HSV space is that hue is the "color", such as red, blue, etc, the saturation -is how intense the color is, and the value is how bright the color is. -

You can get some really nice effects by varying the hue of a color, -because the brightness will not change while you do it. -

-

[return] - - + + + + + + + Utility objects + + + +

+

+Utility objects

+There are a number of objects which were written to make it easier to use +both GEM and pd.  For instance, you often pass around 3 floats at +a time in GEM, either for position or colors.  To help with this, +there are a collection of vector objects.  Use the list below to find +out about the objects. +

These objects used to be in a separate library called MarkEx, but they +have now been folded into GEM. +

counter - count the number of bangs +
average - average a series of numbers together +
change - only output when there is a change in +the number +
invert - invert a number +
randomF/randF - floating point random number +
tripleLine - line object for 3 values +
tripleRand - three random numbers +
vector objects - process a series of numbers +
hsv2rgb and rgb2hsv - convert between RGB and +HSV color space +

+

+counter

+ +
+ +

The inlets are: +
bang (increment or decrement the counter) +
set direction (1 = count up, 2 = count down, 3 = count up and down) +
set low value +
set hight value +
The outlet is the current count. +

So in this case, the top counter will count up from 1 to 10.  +The bottom counter will count up from 2 to 5. +

The counter also accepts the messages reset and clear.  +Reset immediately sets the counter to its low value and outputs the value.  +The clear message means that the next bang will set the counter +to its low value. +

+

+average

+The average object just averages a series of numbers as they come +in.  The left inlet accepts a single float.  It then outputs +the current average.  The default number of floats to average together +is 10, but that can be changed by sending a new value to the right inlet. +

The average object also accepts the messages clear and reset.  +Clear will immediately set all of the values that the object has been storing +for averaging to 0.  With the reset message, you must pass in a number +to set all of the values. +

+

+change

+Change only accepts a number into its left inlet.  If the number +is the same as the last number sent to the change object, then it +does nothing.  If the number is different, then the change +object will output the new number and store it for the next comparision. +

This object is very useful for the == object and others like it, since +they send a 0 or a 1 every time they do a comparision, and you usually +only care when the state actually changes. +

+

+invert

+The invert object is very simple.  If the number sent to its +left inlet is equal to 0., then invert outputs a 1.  If the +number is not equal to 0., the invert outputs a 0. +

+

+randomF/randF

+One problem with the random object in pd is that it only sends out +integers.  This a real problem in GEM, where you often want a value +between 0 and 1.  randomF is exactly like the random +object. +

When the left inlet gets a bang, randomF outputs a random number +between 0 and the given range.  The range can be set with a number +to the right inlet. +

randF is just an alternate name for randomF. +

+

+tripleLine

+ +
+ +

The line object is really great for dealing with a single number.  +To do a line with 3 values, like an RGB color value, means that you have +to unpack, do a line, then repack the number.  Not only is +it a pain, but it expensive computationally. +

tripleLine behaves just like the line object, only it +accepts three numbers to interpolate between.  In the example, tripleLine +will interpolate from the current values to 1., .2, .4 over 1000 milliseconds.  +The default output resolution is 50 milliseconds, which is the same default +rendering time.  Going faster with GEM objects will not produce any +benefit, unless you increase the frames per second. +

+

+tripleRand

+ +
+ +

Just as using tripleLine makes it easier to interpolate between +3 values at once, tripleRand makes it easy to generate three random +values.  In the above example, when the bang is sent, tripleRand +will create three values and output them, with the first between 0 - 1, +the second between 0 - .5, and the third from 0 - .8. +

+

+Vector objects

+The vector math objects are +
vector+ or v+ +
vector- or v- +
vector* or v* +
vector/ or v/ +
All of the above objects perform math on a list of numbers.  The +left inlet accepts a list of numbers of any length.  The right inlet +accepts a single value, which is the operand for the computation.  +In other words, they work just like the normal *, +, -, and / objects, +except they can handle more than one number in the left inlet. +

There are two other objects which are also useful. +

The first is vectorabs or vabs. It computes the absolute +value on a list of numbers. +

The second object is vectorpack or vpack. vpack +accepts a list of numbers in the left inlet and a single number into the +right inlet.  The output is a single list of numbers that is the vector +with the single number appended to the end.  This is very useful when +you want to change the time for a tripleLine without unpacking and +repacking all of the data. +

+

+hsv2rgb and rgb2hsv

+These two objects convert three numbers between HSV and RGB color space.  +HSV stands for hue, saturation, and value.  The simple way to think +of HSV space is that hue is the "color", such as red, blue, etc, the saturation +is how intense the color is, and the value is how bright the color is. +

You can get some really nice effects by varying the hue of a color, +because the brightness will not change while you do it. +

+

[return] + + diff --git a/Gem/manual/WriteCode.html b/Gem/manual/WriteCode.html index d4d0480..1fb8e30 100644 --- a/Gem/manual/WriteCode.html +++ b/Gem/manual/WriteCode.html @@ -1,41 +1,41 @@ - - - - - - - Writing new objects - - - -

-

-Creating new GEM objects

-Look at the source code :-)  GEM is written in C++, which means that -you have to jump through some hopes to interact properly with Pd, which -is written in C.  If you look in Base/CPPExtern.h, you will see a -collection of macros which you can use to help you create new objects.  -Use one of the GEM objects which is closest to what you want to do as a -template. -

One problem on SGI...you will need to -

setenv LD_LIBRARY_PATH "/where/ever/pd/gem" -

so that rld (the run-time linker) can find the GEM dso.  Because -you are linking with GEM, Pd isn't involved with the run time linking process; -it is all done when Pd calls dlopen. -

On NT, there is much the same problem... -

set your PATH environment variable to \where\ever\pd\gem -

or -

make sure that your new .dll is located in the same directory where -GEM is. -

On NT, all of the classes and functions are exported through declexport/declimport.  -You shouldn't have to do anything to call the functions.  I have not -had any problems making other dll's which are loaded into Pd at runtime.  -You need to make certain that you are exporting the correct functions.  -If your dll cannot find the gem.dll, then it will silently fail. -

And of course, e-mail IOhannes m zmölnig (zmoelnig@iem.at) if you have any problems, -questions, or solutions -

-

[return] -
  - - + + + + + + + Writing new objects + + + +

+

+Creating new GEM objects

+Look at the source code :-)  GEM is written in C++, which means that +you have to jump through some hopes to interact properly with Pd, which +is written in C.  If you look in Base/CPPExtern.h, you will see a +collection of macros which you can use to help you create new objects.  +Use one of the GEM objects which is closest to what you want to do as a +template. +

One problem on SGI...you will need to +

setenv LD_LIBRARY_PATH "/where/ever/pd/gem" +

so that rld (the run-time linker) can find the GEM dso.  Because +you are linking with GEM, Pd isn't involved with the run time linking process; +it is all done when Pd calls dlopen. +

On NT, there is much the same problem... +

set your PATH environment variable to \where\ever\pd\gem +

or +

make sure that your new .dll is located in the same directory where +GEM is. +

On NT, all of the classes and functions are exported through declexport/declimport.  +You shouldn't have to do anything to call the functions.  I have not +had any problems making other dll's which are loaded into Pd at runtime.  +You need to make certain that you are exporting the correct functions.  +If your dll cannot find the gem.dll, then it will silently fail. +

And of course, e-mail IOhannes m zmölnig (zmoelnig@iem.at) if you have any problems, +questions, or solutions +

+

[return] +
  + + diff --git a/Gem/manual/index.html b/Gem/manual/index.html index 6d67068..c6739d5 100644 --- a/Gem/manual/index.html +++ b/Gem/manual/index.html @@ -1,67 +1,67 @@ - - - - - - Gem Manual - - - -

-

-GEM Manual

- -
a simple patch
- -

This is the first attempt at a manual for GEM, so bear with me. -Any comments are appreciated. Send them to Mark Danks -

-In fact, this ought to be the second attempt at such a manual. There will not be much now. -But send any comments to IOhannes m zmölnig instead. -

-

Introduction -
    An introduction to GEM and what you can do with -it.  The general system requirements are also described here. -

Using GEM with Pd -
    How to use GEM with Pd.  This includes how -to start Pd so that the GEM library is loaded and working properly. -

Basic objects -
    The basic objects that GEM has.  This section -shows you how to create a simple patch. -

Images -
    Using images is an important part of GEM. Here you -will load in images and learn the basics of dealing with images. -

Texture mapping -
    Loading in images is only one part.  Applying -those images to 3-D shapes is called texture mapping. -

Pixes (image processing) -
    Once you have texture mapped the images, you will -probably want to process and change them in response to user interaction.  -The pix objects provide this functionality. -

Lighting -
    Shading and lighting are easy with the lighting -objects. -

Particles -
    Particle systems can create effects such as smoke, -fire, and water. -

Utility objects -
    To help you deal with the data which GEM uses, there -are a number of utility objects. -

Input devices -
    GEM provides interaction with the mouse and other -input devices. -

Advanced -
    Now that you know all about the other objects, here -are a few of the more advanced ones. -

Writing new objects -
    How to write new objects for GEM. -

FAQ -
    Frequently asked questions about GEM. -

List of Objects -
    All of the objects in GEM with a very brief description.. -

Glossary/Index -
    A collection of definitions and links to explanations. -

-
  - - + + + + + + Gem Manual + + + +

+

+GEM Manual

+ +
a simple patch
+ +

This is the first attempt at a manual for GEM, so bear with me. +Any comments are appreciated. Send them to Mark Danks +

+In fact, this ought to be the second attempt at such a manual. There will not be much now. +But send any comments to IOhannes m zmölnig instead. +

+

Introduction +
    An introduction to GEM and what you can do with +it.  The general system requirements are also described here. +

Using GEM with Pd +
    How to use GEM with Pd.  This includes how +to start Pd so that the GEM library is loaded and working properly. +

Basic objects +
    The basic objects that GEM has.  This section +shows you how to create a simple patch. +

Images +
    Using images is an important part of GEM. Here you +will load in images and learn the basics of dealing with images. +

Texture mapping +
    Loading in images is only one part.  Applying +those images to 3-D shapes is called texture mapping. +

Pixes (image processing) +
    Once you have texture mapped the images, you will +probably want to process and change them in response to user interaction.  +The pix objects provide this functionality. +

Lighting +
    Shading and lighting are easy with the lighting +objects. +

Particles +
    Particle systems can create effects such as smoke, +fire, and water. +

Utility objects +
    To help you deal with the data which GEM uses, there +are a number of utility objects. +

Input devices +
    GEM provides interaction with the mouse and other +input devices. +

Advanced +
    Now that you know all about the other objects, here +are a few of the more advanced ones. +

Writing new objects +
    How to write new objects for GEM. +

FAQ +
    Frequently asked questions about GEM. +

List of Objects +
    All of the objects in GEM with a very brief description.. +

Glossary/Index +
    A collection of definitions and links to explanations. +

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